Strikeforce Welterweight Quinn Mulhern Replaces Sean Pierson, Faces Rick Story at UFC 158

Canadian welterweight Sean Pierson has been forced to withdraw from his UFC 158 bout against Rick Story, UFC officials announced Thursday.

Stepping in to replace Pierson will be ex-Strikeforce talent and former King of the Cage champion Quinn Mulhern, who makes his Octagon debut at the March 16 event. Headlined by a welterweight title showdown between onetime Strikeforce king Nick Diaz and reigning UFC ruler Georges St. Pierre, UFC 158 takes place at Bell Centre in Montreal and airs live on pay-per-view.

Mulhern, 28, has won 10 of his last 11 fights. The well-rounded welterweight relinquished his KOTC title in 2011 upon signing with Strikeforce, where he was defeated in his promotional foray by Jason High. The Brazilian jiu-jitsu black belt responded by posting three straight victories under the Strikeforce banner, most recently taking a spilt nod from highly regarded prospect Yuri Villefort last May.

Also 28, Story looks to rebound from a first-round submission defeat to potent grappler Demian Maia on Oct. 13. The setback served as the third loss in Story’s last four fights, with only a June decision victory over Brock Jardine preventing an 0-4 stretch for “The Horror.” Prior to the skid, Story had won six of his first seven bouts in the Octagon, earning notable victories over Dustin Hazelett, Johny Hendricks and Thiago Alves.