The ordeal for Stanford left tackle Allen Smith continues.
Smith went down again last weekend against Arizona State, his second game back as a starter after being sidelined for two years because of left knee surgeries. The sixth-year senior sprained the medial collateral ligament in his right knee and will need at least a month to recover, coach Jim Harbaugh said Tuesday.
Harbaugh said the extent of the injury has not been determined but he expects the offensive lineman to return before the season ends.
"His goal is to get back and have another shot at Notre Dame at the very least," Smith's mother, Elsie Moore, said of the regular-season finale Nov. 28. "And we're still planning on a bowl."
Smith's best chance to play again would come if the Cardinal (5-3, 4-2 Pac-10) receives a bowl invitation. His loss is a blow to Stanford as it prepares to face Oregon, USC, Cal and the Irish in November.
Moore, an Arizona State professor, was in the stands when her son limped off the field in the first quarter after a Sun Devils player fell on Smith's knee.
"He was finally back and feeling good and contributing to the team beyond being a cheerleader and an informal position coach," Moore said.
The NCAA granted Smith a medical hardship this season for a sixth year of eligibility. He made his debut against San Jose State on Sept. 19 and earned his first start Oct. 17 at Arizona.
Once considered an NFL prospect, Smith's left knee gave out against Oregon in the third game of the 2007 season. After recovering, he suffered a stress fracture in his kneecap during spring camp that left him sidelined for all of the 2008 season.
Andrew Luck's second-quarter touchdown pass to Coby Fleener was nullified because of an illegal formation at the Sun Devils' 37-yard line. The officials ruled receiver Ryan Whalen was out of position and Stanford lost the chance to go ahead 16-0.
"It was as good looking a formation as you will ever see," Harbaugh said. "It was a blown call."
Harbaugh wanted to challenge the decision but said he was told by the referee he couldn't.
The Cardinal coach also didn't like a third-down pass interference call early in the second half against freshman cornerback Quinn Evans. ASU probably would have been forced to punt at Stanford's 44 had the pass been ruled incomplete. Instead, the Sun Devils scored three plays later.