Schaub is coming off his second-lowest passer rating of a disappointing season which has seen him benched twice in favor of Keenum. Yates has been relegated to mop-up duty since tossing three interceptions in a playoff loss to the Ravens two seasons ago.
Here's what else we learned from Phillips' news conference:
» Jonathan Grimes is the only healthy running back on the Texans' roster. Arian Foster and Ben Tate have already been placed on injured reserve. Fill-in starter Dennis Johnson was forced from Sunday's game with a bruised hip, and backup Deji Karim suffered a broken collarbone.
UPDATE: Phillips was asked Tuesday on whether or not Yates would be an option to start Sunday. "Not right now," the interim coach said, via the team's official website.