NORMAN — Just when DeMarco Murray had prevailed over one leg injury, he now faces another. Bob Stoops announced Tuesday that Oklahoma’s sophomore running back will have surgery to repair a partial rupture of his left hamstring tendon and will miss the Jan.8 BCS National Championship game against Florida. Murray was injured on the opening kickoff during the Dec. 6 Big 12 Championship against Missouri. The original diagnosis by the Sooner staff was that Murray had suffered a bruise. But an MRI exam revealed the injury to be more serious. Surgery has been scheduled for next Monday. OU head trainer Scott Anderson said it will be at least five months before Murray can begin working out on the leg again. "Obviously, we’re very disappointed for DeMarco,” Stoops said in a statement. "He has been an important part of our success this year, and we will miss his contributions. DeMarco has had an incredible year.” Murray’s injury means the rushing onus will fall on junior running back Chris Brown and sophomore Mossis Madu. That’s hardly the end of the world. Without Murray, the duo combined to rush for 236 yards and six touchdowns in a 62-21 victory over Missouri in the Big 12 title game. "With Chris Brown and Mossis Madu, we still have two very fine backs,” Stoops said. "Our team has a lot of confidence in their abilities." Murray — who as a true freshman was forced to redshirt while battling turf toe — will begin a long rehabilitation process for the second time in as many years. In 2007, Murray dislocated his right kneecap while trying to recover an onside kick at Texas Tech. He missed OU’s final three games, including the Fiesta Bowl loss to West Virginia. Murray was also held out of spring practice as he recovered from surgery to reattach ligaments in the knee. Early on this season, Murray didn’t display the same explosion that made him a freshman All-American and was often spotted icing the knee after practices and games. But after finishing with just 6 yards on seven carries in a loss to Texas, Murray put the injury behind him, both mentally and physically, and began to resemble his old self. He averaged 94 rushing yards an outing over OU’s final six regular-season games, all blowout victories. Murray also became an outstanding receiving option for quarterback Sam Bradford out of the backfield and finished with 395 receiving yards. He ends the season with 18 touchdowns and a school-record 2,171 all-purpose yards, eclipsing Quentin Griffin’s mark of 2,148 in 2002.