Former UFC champion Mark Coleman (Pictures) has withdrawn from a heavyweight tilt with upstart Brock Lesnar (Pictures) scheduled for UFC 87: Seek and Destroy on August 9 at the Target Center in Minneapolis, Minn., due to a knee injury, UFC.com announced on Thursday.

Coleman, 43, confirmed that he tore his MCL in training and will be sidelined for six weeks. The injury will not require surgery.

The headlining bout would have pitted the former NCAA wrestling champions against one another on Lesnar's home turf in his third professional contest. Lesnar, a former WWE superstar, garnered much attention for his UFC debut on February 2 in Las Vegas - a submission loss to former UFC champion Frank Mir (Pictures).

In its stead, UFC welterweight champion Georges St. Pierre (Pictures) will defend his crown against Jon Fitch (Pictures), a former Division I wrestler at Purdue University. Interim champion St. Pierre, 27, successfully united two UFC titles at UFC 83: Serra vs. St. Pierre II on April 19, avenging a first-round knockout loss to Matt Serra (Pictures) at UFC 68: Shootout in Houston a year before.

St. Pierre will look to snap the 30-year-old Fitch's impressive 15-fight win streak, eight of which unfolded within the Octagon's walls. The American Kickboxing Academy rep outscored a game Chris Wilson at UFC 82 last March.