Arsenal midfielder Granit Xhaka missed last night's 3-3 draw with Southampton due to illness.
Xhaka withdrew on matchday, with Fabio Vieira stepping into the starting XI.
Gunners manager Mikel Arteta confirmed the reason for Xhaka's absence prior to the game.
He said: "Unfortunately this morning Granit wasn't feeling very well. I am excited to see Fabio Vieira in the starting line up.
"Hopefully we have learned a lesson. We know what we have to do but we have to prove it in the moment. Hopefully we will see a very different story."