Houston Texans quarterback Matt Schaub suffered an apparent right leg injury during the third quarter of a 38-13 loss on Sunday to the St. Louis Rams.
Schaub's lower leg bent underneath him on a sack by Rams defensive end Chris Long. Schaub was able to walk to the sideline, but he was replaced by backup T.J. Yates.
"Matt's got a little bit of everything on that one leg, so we'll take a look at it," Texans coach Gary Kubiak said after the game.
More tests are planned for Monday on Schaub's leg.
Houston fans cheered when the embattled Schaub was hurt and Yates trotted onto the field to take over.
But on Yates' first possession and the Texans in the red zone, he threw an interception that was returned for a 98-yard touchdown by Alec Ogletree, giving the Rams a 37-6 lead. Yates had another pass picked off in the fourth quarter.
Houston fans had called for Yates to start after Schaub threw three interceptions last Sunday in a loss to the San Francisco 49ers. Schaub entered the game against the Rams with nine interceptions and eight touchdown passes this season.
At the time of the injury, Schaub was 15 of 21 for 186 yards with no touchdowns or interceptions. Yates finished 12 of 17 for 98 yards.