Lambert will start Sunday's game against the Athletics in Sacramento, Chandler Rome of The Athletic reports.
Lambert was believed to have made his final appearance of the regular season during his 2.2-inning start in Thursday's series opener, but since the Astros have yet to punch their ticket to the postseason, he'll end up getting the ball on two days' rest in Game 162. The Astros will clinch the AL West title with a win or a Rangers loss, so the team is expected to make all of its top pitchers available for Sunday's contest. Given that he's pitching on short rest, Lambert is unlikely to work deep enough into the game to qualify for a win.