Perennial featherweight contender Cub Swanson (15-4 MMA, 0-0 UFC) will have to wait to make his octagon debut.

MMAjunkie.com (www.mmajunkie.com) has learned from sources close to the promotion that Swanson suffered an undisclosed injury and training and has been forced to withdraw from a planned UFC on Versus 3 bout with Erik Koch (11-1 MMA, 0-0 UFC).

With the majority of the promotion's 145-pound fighters already booked for fights, UFC officials are currently seeking a featherweight to take the matchup on short notice.

Featuring a headliner between perennial welterweight contenders Martin Kampmann and Diego Sanchez, "UFC on Versus 3: Sanchez vs. Kampmann" takes place March 3 at KFC Yum! Center in Louisville, Ky.

Swanson had hoped to build on the strength of a November split-decision win over Mackens Semerzier at WEC 52. Swanson finished his WEC run with a respectable 5-3 record that including an impressive three "Fight of the Night" bonus checks.

A timetable for Swanson's return has yet to be established.

Meanwhile, the 22-year-old Koch also hopes to make his octagon debut. The Roufusport-trained fighter compiled a 3-1 record under the WEC banner that includes a "Knockout of the Night" win over Francisco Rivera in November in the featherweight's final bout for the recently-merged promotion.

Koch debuted for the WEC in December 2009 with a win over Jameel Massouh. He returned in March of 2010 where he suffered a decision loss to Chad Mendes. The bout remains the lone defeat of Koch's career.