Carl Jenkinson played an hour for Arsenal's Under-23 side on Friday night after nine months on the sidelines.
The full-back started against Southampton in the latest step on his recovery from cruciate ligament damage.
Jenkinson suffered that injury during a second season on loan at West Ham, but Arsene Wenger indicated earlier this week he believes the boyhood Arsenal fan could still have a future at the Emirates.
"He has been out for a very long time but he's available again to compete now," Wenger said of the once-capped England international.
"It has been very tough for him because he had the knee and after, the shoulders. You think it's endless at that age, you need to be patient.
"He has been patient, resilient and he has a fantastic mentality - he has worked very hard to come back. He had the support of everybody here at the club and I think he has done extremely well."
Hector Bellerin has made the right-back position his own at Arsenal, while Mathieu Debuchy has not even made the bench this season.