Ronnie Shields is a boxing lifer, having twice boxed for the WBC junior welterweight title but ultimately falling short against Billy Costello and Tsuyoshi Hamada during the 1980s. He later put that disappointment behind him, morphing into one of boxing's best trainers.

During that time the affable Texan has worked with a who’s who of boxing including the likes of Mike Tyson, Evander Holyfield, Erislandy Lara, the Charlo brothers and the late, great Pernell Whitaker.

Currently, he's guiding the career of rising heavyweight Joshua Edwards, who caught the eye at last year's Paris Olympics. Since then, Edwards turned professional at the start of the year, been training with Shields in Houston and thus far been kept very active by his promoter Golden Boy.

"He's developing great," Shields told The Ring. "Joshua is one of these guys, he wants to learn, and be the best. No matter who you put him in with, I put him in great sparring all the time and he does a great job doing everything he's asked to do.

"He doesn't mind throwing punches; he likes to fight southpaw and orthodox. He's better orthodox than he is southpaw. He has a tendency, as a southpaw, to throw the other fighter off; he can really punch with both hands."

Edwards (5-0, 5 KOs) appears to have an unquenchable thirst to improve.

"During training, he likes you to be specific on what you want him to do and then on his own he uses it, whether he's going southpaw or right-handed – this is what I really like about him," explained Shields. "I really love the way, as an orthodox fighter, his power in his right hand is unbelievable.

"He's not a really big heavyweight but he's fast, fights like a welterweight; he's light on his feet. He's going to throw a lot of fighters off because they're going to be surprised the way he is on his feet and then really surprised the way he punches."

The rising force has been too much for fellow young boxers and Shields had to deploy a perennial contender in Otto Wallin (28-3, 16 KOs).

"Him and Joshua going at it during sparring sessions is something to watch," he said. "I have to keep reminding them they're in the same team. Other local guys, they couldn't keep up with Josh, he was too fast and strong, they gave him good work, but we had to have two or three of them for them to go three or four rounds apiece."

One of Shields' former clients reminds him of the 25-year-old.

"Joshua reminds me a lot of Holyfield," he said. "He loves to throw combinations and defense; his defense is really slick. He fights more with his hands down than Evander did. Josh has speed, power and that's a combination that's hard to fight."

But of course, reaching Holyfield's lofty highs is still quite some way off but everyone has to start somewhere, and for now, Shields just wants Edwards to stay active.

"Absolutely, and Golden Boy are doing a really good job keeping him busy and that's the thing, they realize Josh is a one of a kind. When you look at the American heavyweights, Josh looks really good, being that guy going to be one of the sport's best U.S. heavyweights.

"I think the way Golden Boy is pushing him, keeping him busy every other month is a great deal. The focus right now is to keep Josh busy and to one day in the next two, three years get him in contention to fight for the world title."