Head coach Gary Kubiak made the announcement during Monday's news conference after practice.
"(Schaub's) health is fine," Kubiak said. "It's a decision based on what I saw take place last week with (Keenum)."
Schaub, who struggled mightily in his first six games of the season, suffered a foot injury during the Texans' blowout loss to the Rams in Week 6, which opened the door for Keenum to make his professional debut against the Chiefs in Week 7. The former University of Houston standout threw for 271 yards and a touchdown in the 17-16 loss.
"(Schaub) is obviously disappointed," Kubiak said. "I wouldn't expect anything else … I know it's a very difficult on him. It's difficult on me, too."