Abel Sanchez, the ex-trainer of former unified heavyweight world champion Andy Ruiz, says the Mexican fighter must be watched closely - or else he becomes lazy when it comes to his work ethic.

Sanchez was in charge of Ruiz's corner for a short period and worked his corner for the 2016 close points loss to Joseph Parker.

Last June, Ruiz was working with trainer Manny Robles when he shocked the world with a stoppage of Anthony Joshua to capture WBO, WBA, IBO, IBF world titles.

But then Ruiz partied for two months, gained a lot of weight, and entered the December rematch with Joshua in poor shape. Joshua easily reclaimed his titles with a twelve round unanimous decision.

A few weeks after that loss, Ruiz parted ways with Robles.

Last week, Ruiz officially announced that he hired respected trainer Eddy Reynoso as his new coach.

Reynoso is best known for his work with Mexican superstar Saul "Canelo" Alvarez, but he also trains several other top fighters.

"Eddy Reynoso must keep him in the gym, make him work and get rid of the baggage around him (the people that surround him and allow him to do things that he must not do)," Sanchez told Sky Sports. "Andy must listen. Eddy is a heck of a coach, one of the best in boxing right now."

Sanchez explained that he went through the same problems with Ruiz that Robles did.

"I'm not there to babysit, I am there to coach and develop you if you are willing to listen. You can't develop someone who doesn't want to try anything. It was difficult for me [to work with Ruiz] because I don't like laziness. We work too hard. I have too many people here working their butts off. To have one person get away with things that nobody else can? That's not proper," Sanchez said.

"He doesn't look like a prototypical heavyweight but he has a lot of ability, unbelievable ability. He lacks in desire. He doesn't want to do things. He finds an excuse not to do something. That's a shame because he could do great things."