Trainer: Mavericks ‘The Only Team’ Cooper Flagg Will Visit Pre-Draft

Cooper Flagg #51 takes part in the Pro Lane Drill during the 2025 NBA Draft Combine (Photo by Michael Reaves/Getty Images)

Every week, Mark Medina shares his thoughts and insights on the latest NBA topics for RG. In this installment, Medina has an exclusive interview with trainer Matt MacKenzie on Cooper Flagg, whom the Dallas Mavericks is expected to select with the No. 1 pick in the 2025 NBA Draft on June 25. The following one-on-one conversation has been edited and condensed.  

You just completed a workout in LA on Wednesday morning [June 11]. What have the workouts entailed overall ahead of the draft?

MacKenzie: “Early on this spring, we were really just focused on getting Cooper prepared for the NBA Draft Combine and some of the workouts that he was going to have to do in preparation for the NBA Draft. But after the combine, it’s really been about getting him up to speed and preparing him for Summer League and the next chapter ahead with whatever team he will be playing with in the NBA.

So we’re really working on a lot of NBA actions. A lot of the work that we do is really spent focusing on game concepts, getting him comfortable moving his body through different types of screens, and getting comfortable shooting off screens. It’s about continuing to refine his overall skill set and help him feel confident and really prepared for whatever type of role he’s asked to fulfill for the next team he’s going to play for.”

You mentioned moving through screens and shooting off screens. What are other examples of the NBA actions and game concepts you all are preparing for?

MacKenzie: “I’ve been studying film on a few different teams and looking at a few different actions they play through, whether it’s high-ball screens, side pick-and-roll, or zoom action. We’re really getting him prepared for how he can be used throughout those different sets and actions, making sure that he’s comfortable no matter what play he’s involved in, whether he’s the ball-handler or the screener. We really just try to get him doing that kind of stuff. We study film first, and then we get on the court to rep it out. I’m really lucky because I have a whole team of coaches that I pull in who can help give him reads.

When we’re in Maine, I usually have five or six guys on the court at all times wearing pinnies, and they have long sticks. We are simulating and mimicking different situations that we’re going to see in-game as much as we possibly can. It’s not just 1-on-0 skill development—it is really conceptual.”

What are the things you’re mimicking?

MacKenzie: “What we’ll do is we’ll set up different advantages. A lot of times, what I’ll do is say, ‘We have a six-second shot clock and we’re going to set you up with one step on your man on the right side of the floor.’ I’ll position the offensive players, and I’ll speak to my defensive players ahead of time and give them an idea of some of the different reads that I’d like to see Cooper have to make. Usually, we’ll take him through four or five different situations per workout. We’ll play games to seven, usually by ones or twos. If the defense gets a stop, we subtract a point from his score.

He has to make good decisions and obviously be able to make the right reads in a short amount of time. I feel like those constraints really challenge him.

That’s what it’s really all about—continuing to find ways to challenge him, not only in his skill development but also in his ability to make good decisions. I feel like that’s what it has always been about. It’s not just about building up his skills but also building up his IQ and ability to be two steps ahead of every play.”

You’ve said in other interviews that you’ve always tried to find new ways to test him and that he’s very competitive. What competitive moments stick out to you during these pre-draft workouts?

MacKenzie: “For Cooper, no matter what kind of drill we’re doing, I always have to find a way to give him something to work toward—whether that’s needing to get a certain score in a certain period of time, so he’s working against the clock; or working toward a target goal in a shooting drill; or if it’s a constraint-based game where he’s working against defenders that I’ve put in place and we’re going to a certain target score there. You have to put some type of competitive aspect into just about every drill with him to really tap into that competitive energy he brings into the gym every day. So, when I’m planning my workouts with him, it’s all about, ‘How can I make sure I put some type of target goal in place so I can make it competitive and really fuel him throughout the workout?’

We usually go to seven by ones or twos. He loses a point every time the defense gets a stop or shuts down his team. Keeping him engaged and challenged in every type of drill, even if it’s 1-on-0—that’s how he operates competitively. That’s what keeps him engaged. He just wants to win at everything he does. Everything he does in life, he wants to win. That’s what is most important. Knowing that about him and understanding how he’s wired helps me put together workout plans that will keep him most engaged.”

Specifically since preparing for the draft, what is your favorite Flagg moment that captured his competitiveness?

MacKenzie: “Specifically since preparing for the draft, there is not necessarily one moment that sticks out. But he’s had a couple of different situations where we’ve thrown different challenges at him and he’s responded really well. Whether it’s been out here in LA working out with the pre-draft guys, where suddenly he’s gotten a little frustrated because his team hasn’t been able to execute or whatever—and then suddenly you see a switch flip and he takes over the game. I can’t think of a specific moment, per se, in preparation for the draft that’s worthwhile for a story. But I’ve been working with him since sixth grade. We’ve had a ton of moments where, suddenly, you see that switch flip and he’s a completely different person because his competitive juices are firing or someone frustrated him and it just made him flip. Over the last couple of months, it’s truly been all about preparing him for the next chapter in his professional career and getting him ready for the NBA. So it’s been a little bit of a different type of training.”

Fair enough. Since you all started working together in the sixth grade, what is your favorite “Cooper Flagg competitive story”?

MacKenzie: “Cooper came to me in the sixth grade. The first time I had a chance to work with him, I saw somebody who had a very clear passion for the game. He loved to be on the floor. He loved to be challenged. He wanted to be pushed. He didn’t mind being coached hard and being told the truth. I think that’s what I enjoyed the most about working with him. The learning curve was so steep, and he was just able to pick up on things incredibly quickly. I was able to put together these constraint-based drills, and he was able to separate through them and pick up on things, even against older, bigger, faster, stronger players, at an incredible clip. As early as seventh grade, I was having him play against varsity high school basketball players, and he was outperforming them on a regular basis.

I think that really made a big difference for him. He had a chance not only to play pickup with guys like that, but he also trained in certain situations with guys who were bigger, faster, and stronger than he was. They were able to weigh in on some of the different nuances of how they played. To be able to share that with an eighth grader was incredibly valuable.”

It’s also reported that some of Cooper’s pre-draft prep has involved Chris Paul and Kevin Durant being at the facility. Is that true?

MacKenzie: “Yeah, Chris Paul and Kevin Durant have been inside the facility. It’s been nice to see how those guys work, and they’ve been really receptive and great about being available to answer questions. They’ve been able to share some of their different strategies in terms of their preparation. Being able to see Kevin Durant work out and then talk to Chris Paul off the court has been very valuable. For Cooper, it’s all about being able to find the right mentors and the right players who have done it before him, so he can continue to take bits and pieces of what has made others successful and allow that to continue to shape him.”

What has stood out to you about what CP and KD do with their work and what messages they have relayed to Cooper?

MacKenzie: “The most important piece has been to be incredibly intentional about your work and understand that sometimes it doesn’t have to be flashy. It’s important to embrace the boring part of things. Sometimes it’s not always going to be different every day. You kind of have to lock in on the small details and nuances of skill development, but also understand where you need to be on the floor at different times and how to work off your teammates.

I think Chris Paul has been really helpful in sharing the different things that you need to be aware of when you’re coming into the league as a rookie in terms of how to manage your time off the court. During your downtime, you need to make sure you’re also treating your recovery with importance and understanding that 82 games is a long season. You want to make sure you really take care of the small details. That way, you can play effectively throughout the entirety of the season. Being able to get that input has been incredibly valuable. It’s nice that those guys have offered words of wisdom to him because certainly they don’t have to do so. It’s been nice.”

How about with KD?

MacKenzie: “With KD, we’ve had the opportunity just to watch him work out. We’ve seen his approach day in and day out, with how incredibly detailed he is with his footwork and how he carries himself not only on the court but off the court. He’s incredibly humble. He keeps to himself. Having Cooper surrounded by somebody like that who can reinforce the little details and how important it is to focus on your footwork—even if it’s for 30 to 40 minutes, to stay refined—is important. Seeing that process, even at the age that KD is, he’s still coming in four to five days a week to put in those extra reps. For Cooper to see somebody who is almost 20 years older than him doing that is very valuable.”

What messages did KD give?

MacKenzie: “To be honest with you, I haven’t heard a ton of interaction with KD other than being able to watch him work out. CP is someone we spend some time with, but with KD, it has been more in passing and seeing him work out. He may have shared a couple words of wisdom with Cooper off to the side, but we haven’t been around him long enough to get to know him at that level.”

Understood, but KD shows a lot with just his work alone.

MacKenzie: “Yeah, his work speaks for itself, really, when watching him and how he moves his body. Some of the different drills he does to improve his footwork and continue to stay balanced have been really neat to watch. Certainly, we’ve picked up on some things there. I started to work in some balance and activation drills with Cooper a couple of years ago. I think it has really helped him a lot with shooting and being able to catch the ball with a good base. I think the way KD approaches his sessions is similar in some ways to what we have built and put in place for Cooper’s activation drills with his foundation.”

ESPN wrote the other day that Cooper plans to meet with the Mavs on June 17. Can you speak to what you all hope comes out of that meeting?

MacKenzie: “Yeah, I think that meeting is really just an opportunity for Cooper to meet the front office and potentially the coaching staff and just get two feet on the ground in Dallas. He’ll be able to tour their facilities and learn about the organization as a whole. So it’s something he’s definitely looking forward to. It’s the only team he’s going to go visit. He’s very excited for it.”

Knowing Cooper well, what are your expectations for what his rookie season will entail?

MacKenzie: “I think time will tell. However, I have very high expectations that he’s going to be able to make an impact right away. Once he gets to the city that drafts him and meets with the coaching staff and starts to learn their playbook and some of their different expectations and has an opportunity to play alongside some of his new teammates, I think he will adjust very quickly. I truly feel he’ll make an immediate impact on both ends of the floor.

Having seen him interact with and play with NBA players before, I am 100% confident he’s ready for that next step. Certainly, like any rookie, I’m sure he’ll have his days. However, when you look at the big picture, I have expectations that he’s going to have a very productive season.”

In the bigger picture, what are your expectations for what Cooper will accomplish in his career and the impact he will have compared to other No. 1 picks?

MacKenzie: “For Cooper, it’s always been about widening the gap between him and other prospects. Every single year, our plan has been to approach it with that same goal. Even though he’s going to be playing at a higher level and will be in the NBA, our goal will always be to continue to maximize his impact in the league and enable him to be the best version of himself he possibly can be. He has very high goals for himself, and I have high goals for him as well. I think he wants to be an eventual All-Star and All-NBA type of player. So he will continue to keep his head down and work, be detailed in his approach every single day, and do everything possible to get there. With that mindset and the way he handles his business, he has a really good chance to become the player he’s dreamed of being his entire life.”

You mentioned that some of his latest work entails getting ready for Summer League. What are the hopes for what he gets out of Summer League?

MacKenzie: “I think every team handles Summer League and their rookies a little differently, so ultimately that will be in Dallas’ hands—or whichever team drafts him. However, from our standpoint, it’s really about making sure he’s in great condition and that he feels like his body is in a good place where he’s ready to step right onto the floor and able to play in back-to-back games if that’s what he’s asked to do.

It’s about being comfortable with playing at the pace required to compete among other NBA players. We’re working on NBA actions every single session. We’re doing a lot of high-volume shooting on the move. There’s a lot of variability within the drills we do. Everything is moving along very quickly, so I think he will 100% be prepared. That is the next step for us—Summer League, and then ramping things up ahead of training camp.”

Can you detail what Cooper’s itinerary has been with his workouts in Maine and LA and the rest of his schedule leading into Draft night?

MacKenzie: “We plan to stay in LA until Tuesday [June 17], when he flies out to Dallas. From Dallas, we’ll have a couple of days off before he needs to be in New York for the Draft. Right now, we’re working through where that location is going to be—it’ll either be at Duke or back in Maine. After a couple of days, we’ll head to New York. Then we’ll start to get ready for Draft week. He’s got a pretty full itinerary for Draft week, with obligations off the court. So we’ll continue to manage those and make sure we find time to get into the gym, most likely the day before the Draft. Then, post-Draft, it’ll be toward whichever city drafts him. From there, it’s up to the team regarding how they want to use him ahead of Summer League.”