Allen went back to the locker room during Saturday's game against the Pistons after being hit in the back of the head, Duane Rankin of The Arizona Republic reports.
Allen took an inadvertent elbow to the back of the head from Simone Fontecchio late in the third quarter and immediately went back to the locker room. While he's off the floor, Phoenix could look to Ryan Dunn and Josh Okogie to pick up the slack.