Arsenal manager Mikel Arteta has confirmed Kieran Tierney will likely miss the rest of this season.
The Scottish left-back injured his knee ligaments against Liverpool last weekend.
Granit Xhaka filled in at left-back in the 3-0 win over Sheffield United on Sunday.
Speaking about Xhaka's performance, Arteta said: "Today he had a really strong performance and he gives you another option.
"Kieran is out, probably for the season so we need different options at that position and he can be one of those."