B.J. Penn willing to break retirement to fight Mike Dolce's 'boy' Nik Lentz

There's no love lost between B.J. Penn and Mike Dolce.

The MMA legend and the famed nutritionist have been at odds since Penn's featherweight loss to Frankie Edgar at The Ultimate Fighter 19 Finale in July 2014.

Fighting at 145 pounds for the first time in his illustrious UFC career, Penn was thoroughly dismantled by Edgar, dropping his third bout to "The Answer" in embarrassing fashion. Following the fight, Penn hinted that there was some animosity between he and Dolce, admitting he would never hire him again.

"I'm sick and tired of talking about Mike Dolce," Penn told "UFC Tonight," according to MMAFighting.com's David St. Martin. "You know what, Mike Dolce? I put a challenge out right now, you go grab Nik Lentz, that's your boy? Bring him down to 145 (pounds). I'll run right through him in one round and then I'll find you in the back and I'll smash you, OK? Let's do that right now. I'm ready."

Dolce blamed Penn's underwhelming performance on a lack of dedication in the gym, a criticism that has dogged the immensely talented "Prodigy" throughout his career.

"Some things were said and this and that," Penn said. "Got me heated. I was there. He was there to work for 20 days. I paid him $1,000 a day. I'm not here to talk about that again but I'm sick and tired of hearing it so many times.

"145. Let's do this. That was my last fight. It didn't go well. I had a very bad showing. I'm ready for something like that. I've been hanging out. I haven't stepped in the gym for two years. I'll come out for the grudge match and we'll see what happens after that."

While Dolce refused to throw more gasoline on the fire, Lentz replied to Penn's challenge on Twitter: