Boxing Trainer Joel Diaz

Let’s talk about Joel Diaz today.

He was the trainer for Ramon Cardenas, who faced Naoya Inoue in the junior featherweight title fight on Cinco de Mayo.

I listened to Diaz’s interview after the bout, and he struck me as a top-notch trainer. Two things stood out in particular.

First is his analytical ability. He clearly understands what his fighter has in his arsenal and knows what to use in which situation. It’s as if he’s running a complex mental flowchart: if one option doesn’t work, he already knows what else to try. After the first round, for example, his immediate concern was whether Inoue’s power was going to be a serious problem. Ramon said no. That allowed Diaz to confidently advise him to keep pressuring Inoue. After all, Ramon had come down from featherweight and had experience dealing with heavier punchers.

The second quality that stood out was his sound judgment. After the knockdown in Round 7, Diaz said to Ramon, “I’ll give you one more f**kin’ round. Why? Because I see you slowing down.” That tells you everything. Speed is a core part of Ramon’s game. And if that weapon is no longer effective, then going toe-to-toe with a fighter like Inoue—the Monster—is a losing battle.

Some people online said the referee stopped the fight too early, but Diaz himself said in the interview that he was ready to throw in the towel when the ref stepped in. That tells you the stoppage was perfectly timed—at least from the perspective of the man who knows Ramon best. Diaz understood exactly what his fighter could still do—and what he couldn’t.

One moment from the post-fight interview really intrigued me. An interviewer asked if the left hook that briefly knocked down Inoue was something they had specifically prepared for. To my surprise, Diaz said no. Honestly, I think he was bluffing. Of course they practiced it. Any serious preparation would’ve involved studying Inoue’s past fights—especially his first-round knockdown against Luis Nery. Diaz could’ve easily said yes. So why didn’t he? My guess is: he didn’t want to show his hand. He wanted Team Inoue to underestimate him.

Why? Because Joel Diaz is going to be in the opposite corner again soon—as the trainer for Murodjon Akhmadaliev, Inoue’s next opponent.

In Inoue’s upcoming bout, his physical talent, mental toughness, and boxing IQ will be as critical as ever. But don’t overlook the strategic element. The trainers play a huge role in shaping the outcome. In other words, the junior featherweight title match in September won’t just be Monster vs. Akhmadaliev—it’ll be Shingo Inoue vs. Joel Diaz too.