A lightweight bout between Clay Guida and Shannon Gugerty is now in the works for UFC on Versus 1 after Guida's original proposed opponent Sean Sherk withdrew from the fight due to an undisclosed injury.

FiveOuncesofPain.com first reported on Friday that the Guida vs. Sherk bout had been scratched from "UFC on Versus 1" card, and Sherdog.com has since confirmed that Sherk had been offered the bout, but turned it down due to a lingering, undisclosed injury.

The full nature of Sherk's injury is not yet known and there is no timetable for the former UFC lightweight champion's return.

Sherk had also been forced to withdraw from his two previous proposed match-ups. The first was a  scheduled lightweight bout against Gleison Tibau at UFC 104 in October. Sherk withdrew from that contest due to a shoulder injury. Then, he was forced out of his bout against Jim Miller at last weekend's UFC 108 after he suffered a deep cut over his right eye in training which required numerous stitches.

Gugerty (12-4) is coming off of a loss against Terry Etim at UFC 105 in November. Prior to the loss, he scored an impressive first-round submission win over Matt Grice at UFC 100 in July.

Gugerty has put together an even 2-2 record with the UFC, suffering a loss in his sophomore effort with the promotion against Spencer Fisher at UFC 90, after defeating Dale Hartt in his UFC debut in July 2008 at UFC Fight Night 14.

Guida (25-11) is currently on a two-fight losing streak, which includes losses against Diego Sanchez at The Ultimate Fighter 9 finale in June, and a second-round submission loss to Kenny Florian at UFC 107 on Dec. 12. Prior to those loses, he's won three straight over Samy Schiavo, Mac Danzig and Nate Diaz respectively.

Guida has put together an up and down 5-5 UFC record since debuting with the promotion in October 2006, scoring other notable Octagon wins over Justin James and Marcus Aurelio. He suffered his other UFC losses to Roger Huerta, Tyson Griffin and Din Thomas.

UFC on Versus 1 takes place on March 21 at The Odeum in Broomfield, Co., and is headlined by a light heavyweight bout between Jon Jones and Brandon Vera.