Last week it was announced that rivals Wanderlei Silva and Chael Sonnen had been booked to settle their long going feud at UFC 173; following filming of TUF: Brazil 3.

But according to Sonnen, "The Axe Murderer" is stressing about getting in the cage with him.

Prior to the two's fight announcement, the pair had already made headlines after they brawled on the set of the reality show last week. It was reported that one of Silva's team Andre Dida, who is a Chute Box veteran like the "Axe Murderer", hit Sonnen in the back of the head during the scuffle.

Silva and Sonnen's rivalry has been an ongoing feud, starting after "The American Gangster" made offensive remarks about Brazil in the build up to his clash with Anderson Silva.

Sonnen has took to Twitter to insult the legendary Pride fighter numerous times and has been keeping his fans update about Silva's antics during the show. The pair almost came to blows just before the series began, after Silva confronted Sonnen at the Mr Olympia bodybuilding festival.

Earlier this week Sonnen continued his attack on his rival coach in an interview with Fighters Only. Sonnen told the website Silva is fat and trying to avoid fighting him at UFC 173.

“Wand is fat. He hasn't taken his shirt off since we have been here,” Sonnen said. “He thought our fight would be in July, but it got announced for May. He's stressed and trying to get out of it.”

Silva hasn't fought inside the cage since March last year due to injuries. In his last night he won a FOTN battle over Brian Stann, which also earned him "Knockout of the Night". If "The Axe Murderer" isn't in shape we will certainly find out come May 24.

The pair will finish filming TUF: Brazil 3 later this month, the season will be available to watch from March on Fight Pass. If all goes well the two will settle their score at UFC 173 in the co-main event. Let's just hope Silva isn't too "fat" and the fight goes ahead as planned.