Osweiler replaced Tom Savage in the Texans' Week 17 loss to the Tennessee Titans after Savage left the game with a concussion. Osweiler had been previously benched for Savage in Week 15 after he threw two first-half interceptions.
In Saturday's 27-14 victory over the Oakland Raiders in the wild-card round of the playoffs, Osweiler was 14-of-25 for 168 yards and a touchdown. He also ran for a one-yard touchdown, and did not turn the ball over for just the third time this season in a game he started.
"I thought [Osweiler] had a good game," O'Brien said. "He took care of the ball, he executed the game plan. Basically he spread the ball around; I'm not sure how many receivers caught passes but it looked good to me. I thought the offensive line had a nice game for the most part.
"We had a couple breakdowns but I thought they played better than they had been playing. I think we rushed for over 120 years which is good. I think any time we do that we have a chance to win in addition to taking care of the ball. Everybody on offense did a nice job today."
Savage is still in the NFL's concussion protocol, so quarterback Brandon Weeden served as Osweiler's backup on Saturday.
The Texans signed Osweiler to a four-year, $72 million contract during the offseason, but he has struggled for most of the season, with 16 touchdowns and 16 interceptions in 15 regular season games and Saturday's playoff victory.