Laurent Koscielny appeared to suffer a new injury setback after hobbling off in Arsenal Under-21's Checkatrade Trophy defeat to Portsmouth at Fratton Park.
The defender has been fighting back to fitness after rupturing his Achilles tendon against Atletico Madrid in May.
He managed 45 minutes in the side's previous Checkatrade Trophy game against Derby, but had to be removed five minutes from time against Pompey.
There was no clash with an opposing player so it’s hard to tell exactly what happened.
One second Koscielny was tracking back to defend, the next he was coming off with the physio.