A middleweight bout between Trevor Prangley and Robbie Lawler set for this weekend's Strikeforce: "Evolution" event was scratched from the card after Prangley suffered an undisclosed injury in training according to Sherdog.com.

According to the report, the nature and severity of Prangley's injury is not yet known and Strikeforce is currently seeking a replacement opponent for Lawler, however, the promotion may find a hard time nailing down a replacement with the event set for this Saturday.

Prangley was replacing Lawler's original opponent for the event, Benji Radach. Radach was unable to face Lawler after failing to gain medical clearance to begin training following surgery on his right hand this past April.

Prangley (22-5) was looking to extend his winning streak to six fights. He recently picked up his fifth-straight win by defeating Marcus Sursa at Shark Fights 7 on Nov. 28. Prangley has not been defeated since losing to Jorge Santiago in November 2007. The American Kickboxing Academy product sports a 3-1 record in four fights with Strikeforce, scoring wins with the promotion over Falaniko Vitale and Anthony Ruiz (x2).

Lawler (16-5), who is the former EliteXC middleweight titleholder, hasn't fought since having his six-fight unbeaten streak snapped at the hands of current Strikeforce middleweight champion Jake Shields via first-round submission at Strikeforce "Lawler vs. Shields" in June.

Strikeforce: "Evolution" takes place on Dec. 19 at the HP Pavilion in San Jose, Calif, and is headlined by a lightweight title unification bout between Strikeforce lightweight champion Josh Thomson and interim lightweight champion Gilbert Melendez.

In addition, middleweight sluggers Cung Le and Scott Smith will battle it out. Other bouts featured include; Matt Lindland vs. Ronald "Jacare" Souza and Muhammed "King Mo" Lawal vs. Mike Whitehead.