Henrikh Mkhitaryan will miss Arsenal's Premier League game with Southampton on Sunday after picking up a knee knock against CSKA Moscow, while David Ospina faces up to three weeks out with an ankle problem.
Arsenal cruised to a 4-1 triumph over the Russian side at Emirates Stadium on Thursday, with Aaron Ramsey and Alexandre Lacazette getting two each.
The comfortable lead leaves them in the driving seat in the Europa League quarter-final tie, though a seemingly innocuous injury suffered by Mkhitaryan just after the hour could prove a blow, with Wenger expecting him to at least be out of Sunday's game.