TCU will be seeking backfield options after running back Waymon James was ruled out for the season with a knee injury Wednesday. (AP Images)

TCU's offense sputtered in last week's win over Kansas, but it suffered a bigger blow in the fourth quarter against the Jayhawks, as the school confirmed leading rusher Waymon James is out for the season with a knee injury.

The news was first reported by Stefan Stevenson of the Fort Worth Star-Telegram. James, who was also the team's leading rushing in 2011, had gained 168 yards through TCU's first two games, including 99 rushing yards in the 20-6 win over the Jayhawks. 

James' injury did not appear to be induced by contact, as he fell to the ground after planting to make a cut. Initially, it appeared the injury was not serious -- according to Stevenson, Horned Frogs coach Gary Patterson indicated James would be a game-time decision this week against Virginia -- but Wednesday, the school announced the injury would keep the junior out for the year.

Although losing the team's leading rusher is hardly ideal for Patterson and TCU -- especially as it has only Big 12 games remaining after this week's game against Virginia -- there is another experienced running back ready to take over. 

Senior Matthew Tucker rushed 19 times for 100 yards in the team's first two games. His 5.3 yards-per-carry average is considerably lower than James' 9.9, but Tucker does have the ability to hit for the occasional big play, as he had a 29-yard run Saturday.

"In my profession you can't worry about the guy that goes down," Patterson said at his Tuesday press conference, according to Stevenson. "It's got to be about the next guy needs to step up. Matthew had the best spring and summer of all of them. He's been a great running back for us for a while."

True freshman B.J. Catalon (15 carries for 61 yards this season) and senior Aundre Dean (eight attempts, 29 yards) could also figure into the rotation with James out for the season.

If Patterson doesn't have as much faith in Tucker, Catalon and Dean to carry the load, it could alter TCU's run-pass balance, which has been one of the team's strengths this season. The Horned Frogs have passed for 60 percent of their 1,018 yards of offense and run for the other 40. Replacing James' production, then, could fall on the shoulders of QB Casey Pachall, who leads the nation in passer efficiency rating (242.37).

For more up-to-the-minute news and analysis from Big 12 bloggers C.J. Moore and Patrick Southern, follow @CBSSportsBig12 on Twitter. You can also follow C.J. (@cjmoore4) and Patrick (@patricksouthern).