The five-time All-Star played in the Rockets' season-opening victory over the Sacramento Kings and was projected to miss three weeks.
Instead, he was out only three games, all losses.
"I've been out six days and it's tough to get myself back into great playing shape," McGrady said. "It's going to be a test to see how I handle it tonight. The back is fine, no pain, no tightness."
McGrady returns just in time for head coach Jeff Van Gundy.
"I think our game stinks when it counts the most," Van Gundy said. "It's random, undisciplined, helter-skelter, Rockets gone wild."
McGrady will provide a steadying influence.
"What I do is keep the team under control," McGrady said. "The ball is my hands more so than anybody else. I control the game and how it's played."