Heavyweight contender Dillian Whyte is questioning the drive and desire of IBF, IBO, WBO, WBA world champion Anthony Joshua.
Back in 2015, Joshua knocked out Whyte in the seventh round of their grudge match.
In a recent interview, Joshua acknowledged that he was nearing the end of his career - with a five year period, at most, to continue in the sport.
Whyte views the recent statements as some type of sign that Joshua's motivation to continue his career is declining.
He regards Joshua as being more of a businessman than a fighter.
"Maybe he's comfortable, maybe his drive and desire is going down," Whyte told Sky Sports.
"He seems to be fighting a lot more defensively than he used to do. Maybe he's thinking, 'You know what, I haven't got long left, it's a hard game.' "When you achieve everything you've set out to achieve and you've got lots of money, sometimes you think, 'You know what, let me just retire and go and do something else.'
"He doesn't strike me as someone who loves fighting. He loves the business and he loves the opportunities. Obviously he's a good athlete and a good boxer, but he doesn't strike me as someone who loves to fight. I love fighting. I enjoy fighting for the sake of fighting. That's why I'll fight anyone and I'm always ready to go."
Joshua was in action last month, when he knocked out IBF mandatory challenger Kubrat Pulev in nine rounds.
At the moment, Joshua is negotiating a potential two-fight deal for a full division unification against WBC champion Tyson Fury.
Whyte was in the ring back in August of last year, when he was knocked out in five rounds by Alexander Povetkin. After several postponements, a rematch with Povetkin is being targeted for a date of March 6th.