This being the lightweight division, though, means there's always one guy to call who will no doubt accept any fight that comes his way and today is no different. Donald Cerrone has agreed to step in for Stout against Siver in "Sin City."
ESPN.com passed along word earlier today.
Cerrone last competed just over two weeks ago today, impressively knocking out Charles Oliveira in the very first round. It was the third win this year for "Cowboy," who made the jump from the now defunct WEC after a Dec. 2010 win over Chris Horodecki.
He's 3-0 inside the Octagon and on a five-fight winning streak. And with his penchant for stepping up on short notice, you can bet the Greg Jackson product is knocking on the door to a title shot.
It shouldn't be held against the Russian-born German stick of dynamite, though. He's 8-1 in his last nine bouts and has improved remarkably since returning for his second stint with the world's largest fight promotion.
But can he reach the top? The journey continues against Cerrone.
UFC 137 will feature welterweight champion Georges St. Pierre putting his title -- and legacy -- on the line when he goes head on against former Strikeforce king Nick Diaz. The co-main event will highlight a potential number one contender bout pitting B.J. Penn vs. Carlos Condit.
For the latest UFC 137: "St. Pierre vs. Diaz" news and notes click here.