Houston Texans running back Arian Foster, who sat out the final 10 minutes of Sunday's 31-17 loss to the Tennessee Titans, cited a muscle spasm in his glute -- not his sore ankle -- as the reason for leaving the game, according to the Houston Chronicle on Monday.
Foster missed practice time before the Titans game with an ankle sprain.
Foster has burst onto the scene in his second season. He rushed for 257 yards in 2009, but eclipsed that number in his first two games this season following a 231-yard outburst against the Indianapolis Colts in Week 1.
The Associated Press contributed to this report.