Kenny Robertson (photo via UFC.com)

By Timothy J. Gilbert

An undisclosed injury has forced T.J. Waldburger out of his welterweight bout against Sean Pierson; Kenny Robertson will fill in for their UFC 161 match.

UFC officials announced the replacement Thursday via Twitter.

Robertson (12-2) returns after earning “Submission of the Night” when he tapped Brock Jardine with a kneebar at UFC 157. He was 0-2 in the UFC before this win dropping two matches over two separate stints in the UFC.

He will fight Pierson (13-6) a native of Canada who broke into the UFC with a win over Matt Riddle at UFC 124. Since then he is 2-2, winning his last two matches against Lance Benoist and Jake Hecht, and looks to continue the streak in his first fight in almost nine months.

Waldburger (16-7) was 2-1 in 2012 and was coming off of a “Submission of the Night” victory over Nick Catone prior to getting hurt. No details regarding the nature of his injury were released.

They will face off at UFC 161 scheduled for June 15 at the MTS Center in Winnipeg, Manitoba, Canada. An interim bantamweight title fight between champion Renan Barao and Eddie Wineland headlines the event.