Roy Nelson rarely appears to be at a loss for words. Over the years, he's been one of the most opinionated fighters on the UFC roster, voicing his two cents on topics from PEDs to fighter pay. But almost a week after getting the call to coach the upcoming season of The Ultimate Fighter -- a show in which he was once a participant -- Nelson remains essentially speechless.



"My reaction is I think I’m still reacting," he said on Monday's edition of The MMA Hour. "I’m still just dumbfounded."



Nelson said he got the first inquiry about his participation last Wednesday night, and by Thursday, the offer had become official. His selection came as a bit of surprise to most, particularly given his volatile relationship with UFC president Dana White. And while those two seem destined to butt heads during the show's taping, it seems like we should expect the same between Nelson and opposing coach Shane Carwin.

The two have engaged each other in social media a bit over the last couple of years, starting in August 2010, shortly after Carwin was revealed on a list as one of 22 professional athletes who had obtained steroids through an online pharmacy based in Mobile, Alabama.



That was the genesis of a simmering rivalry that might finally get some resolution when the two meet after coaching the show, but not before a few more shots -- both verbal and written -- are fired.



In a recent blog entry after earning the TUF coaching role, Carwin took aim at Nelson, writing in part, " I know Roy likes to be the UFC’s jester but he better know this is not a joke for me. He can keep striving for being average, I am pushing myself and those around me to find the American Dream. The dream that comes from lots of hard work and sacrifice, no gimmicks necessary."



Asked for his reaction, "Big Country" at one point wondered "if Shane's bipolar," and then said he welcomed Carwin's opinion, even if it was pointed.



"It sounds like he’s a Chael [Sonnen], which is OK because I can be Anderson [Silva] and put him in his place," he said. "I have no idea [if he's putting on an act]. My thing is, I don't know if he’s getting off his meds or what it is. But for me personally, it’s OK to be average. But the thing is, hard work does pay off. I’m just average and look at the s--- that I’ve pulled off. I’m coaching The Ultimate Fighter."



One issue of Carwin's statement that Nelson did have a problem with was the insinuation of him being a jester, noting his past success in coaching fighters.



"I’ve never had any complaints about my coaching ability," he said. "I've coach UFC champions and stuff before I ever started fighting."



Throughout the 20-minute interview, Nelson dropped several references about Carwin's alleged steroids link. While he was never charged with a crime in the case, Nelson clearly believes that where there is smoke, there is fire, even if he did call Carwin a "clean fighter" by the end of the interview.



"I said he is a clean fighter," he said. "I only fight clean fighters. I'll fight anybody in the UFC that's clean. Or dirty. Or clean."

Nelson said he hopes to use the fight to vault him into a potential matchup with current champion Junior dos Santos.