Detroit Lions linebacker CJ Mosley has admitted that he has no idea as to what teammate and controversial defensive tackle Nick Fairley is thinking, after disappointing coaches with his weight during the off-season.

Fairley has widely been touted as potentially one of the most talented defensive men in the league, but his teammates are growing increasingly frustrated by his lack of dedication ahead of the new season.

"I don't know where his head's at. I wish I knew," Mosley said of his teammate, according to MLive.com.

"If I knew, man, I'd grab his head and bring it back to where it's supposed to be. I just don't know.

"I try talking to him, and I try encouraging him. That's something I've always done. I love Nick, man, and just want to see him reach his potential. That dude doesn't know how good he could be. And it hurts to see him like this."

The new NFL season is due to commence next month.