by Steven Marrocco – MMAWeekly.com
A rematch between rivals Nick Diaz and Joe Riggs is set for the main card of Strikeforce “Carano vs. Cyborg” on Aug. 15. The bout will be for the newly created welterweight title.

Sources close to both fighters confirmed the news to MMAWeekly.com on Monday. An announcement from the promotion is expected shortly.

It is the fourth title fight confirmed for the late summer card. Gina Carano faces Cristiane “Cyborg” Santos for the women’s 145-pound belt, Josh Thomson defends his lightweight strap against Gilbert Melendez, and heavyweight champion Alistair Overeem defends against Fabricio Werdum.

Bad blood remains between the fighters. Following Riggs’ decision victory over Diaz at UFC 57, the two brawled in a Las Vegas hospital until broken up by security. Both hit career skids later in 2006 and were released from the UFC.

Since the acquisition of his ProElite contract in February, Diaz has made a splash in Strikeforce, defeating Frank Shamrock and, most recently, Scott Smith. The Riggs bout will be his first at 170 pounds since his last UFC appearance against Gleison Tibau in November 2006.

Since his exit from the UFC, Riggs has re-invented himself in Strikeforce, going 4-2 for the promotion. The Arizona Combat Sports fighter was scheduled to face Jake Shields in April, but Shields turned down the fight. Riggs has since been unable to book the fight despite calling Shields out on several occasions. Shields went on to headline against Robbie Lawler in June.

Riggs defeated Phil Baroni on the same card, and believed incorrectly that he broke both hands during the fight. A subsequent doctor’s visit confirmed that he had merely bruised bones in his wrist, and he will make a full recovery for the August fight.