Texans quarterback T.J. Yates left Sunday's 23-22 loss to Tennessee in the first quarter after landing on his left shoulder following a hard hit.
Coach Gary Kubiak said Yates had a bruised left shoulder but could've returned if necessary. Kubiak also said Yates would undergo more tests Monday.
"Obviously, I didn't want him to go back in the game," Kubiak said. "We'll know better where we're at (Monday), at this point."
Yates was replaced by veteran journeyman Jake Delhomme.
The 36-year-old Delhomme, signed Nov. 29 in the wake of season-ending injuries to starter Matt Schaub and backup Matt Leinart, completed 18 of 28 passes, including a 5-yard touchdown pass to Bryant Johnson with 14 seconds left.
Houston (10-6) was already locked into the No. 3 seed in the AFC playoffs and rested a majority of its starters in Sunday's game.
Information from The Associated Press contributed to this report.