The Chilean is a major doubt for the Aston Villa tie.
Arsenal take on Aston Villa this Sunday at The Emirates Stadium and much of the excitement ahead of the game will be around the potential debut of new signing Gabriel Paulista. Arsene Wenger has today given an update on team news ahead of the game.
While Arsenal fans may just get a chance to see their new star in action, their big name signing from the summer might not be available. Wenger has confirmed that Alexis Sanchez could be unavailable for the game because of a hamstring problem.
He told the official Arsenal website:
"The squad will be exactly the same as last Sunday [v Brighton]. The only uncertainty we have is Alexis Sanchez who has a hamstring concern, and that will be decided on Saturday. He might be out for Sunday. The only [other] difference is that Gabriel is available and we’ll check him how he is physically but he should be alright to be available."
Alexis has been the star of Arsenal's season so far. Since joining from Barcelona inn the summer he has scored 18 goals for the club in all competitions - with his tireless work rate and positive attitude also a big boost for the Arsenal faithful.
Arsenal will also still be without Danny Welbeck. The former Manchester United forward is yet to play in 2015 after picking up a thigh problem against West Ham at the end of December.
Wenger offered an update on his progress and insisted that Welbeck will be fit for the North London derby next weekend.
"Welbeck is very close. He is really, really, really nearly there. He will be available for the Tottenham game."
So good and bad news, as always, from Arsene Wenger in his weekly update.
What does this mean for Arsenal?
With Alexis and Welbeck missing the likelihood is Theo Walcott will start the game against Villa. Mesut Ozil is also likely to retain his place in the first-team - with the likes of Joel Campbell and Lukas Podolski now loaned out options are not quite as fruitful in the attacking area, so expect to see Chuba Akpom in the squad once again.