UFC welterweight TJ Waldburger as of Thursday, May 2nd, has been forced out of his bout with Sean Pierson at UFC 161 for reasons unknown.

UFC Officials have stated that with Waldburger out, Kenny Robertson would be stepping up to replace him against Pierson. Robertson is most recently known for his first round kneebar submission over Brock Jardine back in February. He will be looking to show the UFC that he belongs in their talent rich welterweight division, and will have the chance to make that statement in the octagon at UFC 161.

Sean Pierson on the other hand will be looking to continue a two fight winning streak that could take him a step up the latter in UFC welterweight competition. Pierson is (3-2) in the UFC and will be eager to get back to the cage with his last outing being in September of 2012.

The two will face off in the third fight of the night, at UFC 161 Barao vs. Wineland on June 15th at the MTS Centre, Winnipeg, Manitoba, Canada.