Mikel Arteta admits he is unsure when Takehiro Tomiyasu will be fit to return for Arsenal.
Right-back Tomiyasu, who established himself as first choice following his summer arrival from Bologna, has missed Arsenal's last five games after aggravating a calf problem, with Cedric Soares's deputising ably.
The defender appeared to be over the issue that has troubled him for the last couple of months when he returned for Arsenal's Carabao Cup semi-final second leg against Liverpool but Arteta fears he may have come back before he was fully ready.