Laurent Koscielny’s comeback from a long-term injury suffered a setback as he limped out of Arsenal U21s defeat at Portsmouth in the Checkatrade Trophy on Tuesday night.
The 33-year-old was making his second appearance of the season following a serious Achilles injury he suffered against Atletico Madrid in May.
But the Frenchman, who has yet to return to the first team, was forced off in the 85th minute with an injury as Arsenal U21s lost 2-1 at Portsmouth.
The club captain was assessed by Arsenal’s medical staff after Portsmouth’s winner with the nature and extent of the injury yet to be confirmed by the club.
Koscielny made his comeback last month for Arsenal U23s in their 5-0 loss at Derby U23s, where he completed 45 minutes.
Since joining from French side Lorient in 2010, Koscielny has made 324 appearances for the Gunners, scoring 24 goals.