Strikeforce recently announced four more participants for its Nov. Challengers Series event. Ben Holscher, Casey Olson, former Strokeforce light-heavyweight title contender Anthony Ruiz, and female prospect Zoila Frausto,will all compete on the card. Opponents for all four competitors will be named at a later date.

Strikeforce Challengers: "Evangelista vs. Gurgel" will take place on Nov. 6 at the Save Mart Center in Fresno, CA, and the main card airs live on Showtime. The event will be headlined by lightweight bout between UFC veteran Jorge Gurgel and undefeated prospect Billy Evangelista.

Ruiz (22-13) is coming off a win over Gan McGee at Pure Combat 9 in July. Prior to the win, he had lost two straight fights against Trevor Prangley and Aaron Rosa. Ruiz is 1-4 in five fights with Strikeforce, with a lone win over Bobby Southworth. He has been competing professionally for six years, fighting for such promotions as EliteXC, WEC, Palace Fighting Championship and Gladiator Challenge. Ruiz has finished 16 of his 22 career wins, and he holds other notable victories over Jimmy Ambriz and Brad Imes.

Holscher most recently defeated Cody Canterbury at the May 15 Strikeforce Challengers series event. He is off to a 2-0 start to his young MMA career, with his first career win coming against Walt Hughes at War Gods: "Do or Die" in Nov. 2008.

Olson (10-3) suffered a first-round submission loss against Eddie Yagin in his last bout at PFC 13:"Validation" in May. Prior to the loss, he had won four straight, including three of those wins coming by submission. Olson previously fought for Strikeforce in Oct. 2006, where he defeated Bobby Sanchez. Six of Olson's 10 career wins have come via stoppage, and he holds a notable win in his career over Tito Jones.

Frausto moved her career record to 2-0 with a unanimous decision win over Leann Jenkins at July's Pure Combat 9: "Home Turf." She previously defeated Karina Hallinan via split decision at the Wargods/Ken Shamrock Productions co-promoted event, 'The Valentine's Eve Massacre' in Feb.