Gennady Golovkin says his new trainer, Johnathon Banks, will be able to get him to the next level of his fighting career. (1:00)

When former unified middleweight world titleholder Gennady Golovkin decided to move on with the final chapters of his career without longtime trainer Abel Sanchez, with whom he had a long and successful partnership, the announcement came as a bit of a shock. In as the new trainer is Johnathon Banks, a former heavyweight fighter-turned-trainer who learned from the legendary Emanuel Steward at the Kronk Gym in Detroit and recently worked with former heavyweight champ Wladimir Klitschko and undisputed welterweight champion Cecilia Braekhus.

This union will be tested on Saturday, as Golovkin faces Steve Rolls in a super middleweight bout at Madison Square Garden in New York.

ESPN asked a group of leading trainers for their thoughts on the 37-year-old Golovkin and what adjustments they would have him make under their guidance.

Teddy Atlas

Notable trainees: Michael Moorer, Oleksandr Gvozdyk, Timothy Bradley Jr.

Gennady Golovkin, right, should use the jab more to set up his power punches, according to Teddy Atlas. Ramsey Cardy/Getty Images

Golovkin shouldn't be dependent on just his physical assets, which are obviously his strength. He's no longer the biggest guy in town all the time. So be creative, look for options, add to what's there, and let him use his jab as more than just a snow plow to clear out the driveway in front of him. Let him throw an uppercut or a hook off it. Let him be more creative in those ways to create other things.

Help him in some ways where he has become one-dimensional from a defensive standpoint, where he's either blocking or sometimes he'll just take a little step out of range. Let him work more on getting to the sides sometimes. I'm not saying he's the most fleet-footed guy or he's [Vasiliy] Lomachenko or that he can do the same things -- I understand that better than most -- but it doesn't mean he can't do some of the things at the level [Lomachenko] can do them and that he can add to what he does and work on some head movement.

I see him as a straightforward guy. I think his opponents see him that way. Make use of feints, let him set traps once in a while. The feints would obviously be productive for him because people are going to believe he's coming forward, and he's going to get reactions and get people to bite on it because they know the body of work. So give yourself help in those areas -- but don't rely just on your physical attributes and your mental attributes, which is something he has relied on. He's very determined, very steadfast, very resilient.

You look at [Marco Antonio] Barrera. Barrera added a lot. He doesn't get enough credit. He was a straightforward guy, in some ways very similar to GGG. He took it away from you. He did that 'til he ran into guys who could take it and neutralize him like Junior Jones. He faced him, got beat with a right hand, and he got stopped. To his credit, he didn't just come back determined, he came back in a different way, he came back determined to change things, determined to improve, determined to add things, determined to give a different look, and he sure as well did.

A lot of people at that stage of his career thought it would be over because he already took a lot of wear-and-tear, and you "can't teach an old dog new tricks" and all that crap, and sure enough, he changed his whole approach. He became a boxer. When he had to come get you, he came and got you, but he did it in a more efficient way and, in the end, the more effective way. He stayed around a long time and beat a lot of good fighters and dangerous fighters that he might not have beaten if he hadn't made those changes.

Ronnie Shields

Notable trainees: Vernon Forrest, Kermit Cintron, Pernell Whitaker, Erislandy Lara, Jermall Charlo, Efe Ajagbe

Gennady Golovkin, right, wasn't that aggressive against Canelo Alvarez in the rematch as he was in their first fight in 2017. Al Bello/Getty Images

I don't see [Golovkin] much different to me. It's the same guy. I don't think he's lost much. He's lost a little bit, but I don't think he's lost a lot.

Really, what I would do is I would have to see him training, I'd have to take a look at him first, for a few days just to assess everything. I would personally go back and look at his last four fights and see what I think are the things that can be improved on. That's what I do with fighters I have never trained before.

In the rematch with Canelo [Alvarez], I noticed he didn't throw any punches. He tried to box Canelo -- why would you box Canelo when your style is basically as a come-forward guy who throws punches? So I didn't understand him backing up. That didn't sit well with me. I didn't think that was good for him. I think he should've made Canelo get into a fire fight.

Look, Golovkin can punch. He's a strong guy. He fights good when he comes forward. I just didn't understand. He did it in the first fight with Canelo. He had a lot of success in the first fight, but the second fight he came out the opposite way. That didn't make sense to me.

Stephen Edwards

Notable trainees: Julian Williams, Kyrone Davis, Romuel Cruz

Gennady Golovkin, left, has a powerful left hook to the body that can hurt any opponent. Ed Mulholland/Getty Images

I'm not second-guessing anything Abel did because I respect him as a coach. But I noticed -- and I don't know why -- Golovkin has only been able to really land his jab against Canelo in 24 rounds and 12 rounds against Daniel Jacobs. I don't know what happened with him once he met those guys, but he used to be able to land a variety of punches.

He had a big left hook to the body that he would hurt people with. He had looping shots upstairs. He had a really, really good, two-fisted attack. But for some reason, against those guys, he was able to stay in the fights only with the jab. So I would look and see if he was catching his rhythm and if he could put more hurt on those guys with more than just his jab. Some people think he won all three of those fights, but at the end of the day, it would be beneficial to him if he was able to go back to more of his two-fisted attack and figure out why he was able to land only the jab.

I would say that he got comfortable with landing [the jab], and for whatever reason, he didn't put other punches together. But maybe you have to give these other guys credit for taking those other punches away. In the Canelo fight, what I noticed is that Canelo is a master counter-puncher, so maybe he discouraged Golovkin from throwing the bigger shots because when you throw them, you leave yourself a little bit more susceptible.

Joel Diaz

Notable trainees: Bradley, Lucas Matthysse, Israil Madrimov, Diego De La Hoya, Ruslan Provodnikov

Gennady Golovkin fighting defensively against Canelo Alvarez in their matchup last September was a concern to several of boxing's top trainers. Al Bello/Getty Images

I'd be working on combinations, using range, moving and angles. Golovkin is basically a straightforward power puncher. If I were training Golovkin, I'd teach him how to use the ring, move, teach him how to walk backward as he's fighting, not just going forward for the kill.

I don't think one camp can make a difference. I've done it with other fighters. [Banks] will make a little bit of a difference but not enough. He needs at least a minimum of three camps with him so you can see a good difference. I've had fighters in my camp before -- Victor Ortiz, Francisco Vargas, guys that have been "made" fighters already -- and it took two or three camps where I could see a change in them.

The first camp you're going to try to remind them of all the new changes, but you're basically going to see the same Golovkin with a very minimum of difference.

Freddie Roach

Notable trainees: Manny Pacquiao, James Toney, Virgil Hill, Angel Acosta, Miguel Cotto, Alberto Machado

Gennady Golovkin, left, had some problems trying to cut the ring in his fights against Canelo Alvarez. John Gurzinski/Getty Images

I think [Golovkin] has slowed down a little bit, but that naturally happens. When I got Miguel Cotto, he was older, and the first thing I did was adjust his running program, and I didn't make him run so much because I think the long runs were killing him. So we shortened up the runs and had much better performances.

At this point, they are pretty much who they are -- you can't change them. When people try to change somebody, it's foolish. You can't change people. He knows what he does best, so why not stick with what's been working for years?

What I noticed in the rematch with Canelo was that his movement wasn't nearly as good as it usually is. Before, he could cut the ring off, and he was very mobile and so forth. It didn't seem like his legs were quite there. They weren't strong enough to carry him through the whole fight.

But Golovkin definitely has another good year or two left, and it should be exciting because the thing is when great fighters slow down a little, they're a little more accessible to getting hit. It makes for better fights.

Joe Goossen

Notable trainees: Michael Nunn, Gabriel and Rafael Ruelas, Joel Casamayor, Diego Corrales, Sergey Lipinets

Trainer Joe Goossen would like to see Gennady Golovkin, right, throw more combination punches. Al Bello/Getty Images

First off, I just want to say that I think Abel Sanchez did a great job with Golovkin, taught him a lot of stuff. They won a ton of fights with each other and had a great run. I honestly don't think you can find fault with the job he did.

That said, Golovkin's older, so not everything is going to be as it was, and you're going to rely more on your experience as you lose a little of your speed. But if I would've had him here, I definitely would've worked on more combinations and doing more of the things he was doing a few years ago. The past couple of years, I think he went down a little bit in terms of output with his punching. It's something where I'd have to see him up close in my gym.

He was a very, very aggressive guy. I think he was very aggressive in that first fight [with Canelo], but Canelo didn't oblige him much. He was on the move. The second fight, Canelo fought him more. His inside game could've been a little more active against Canelo, I think.

But to me, that's a fallacy that you can't teach somebody, a veteran, new tricks. And even if it isn't a new trick, it can be a new plan. But again, I really respect the job that Abel did with Golovkin.