Alex Oxlade-Chamberlain: Arsenal midfielder has a hamstring injury

Arsenal are waiting to find out how long Alex Oxlade-Chamberlain will be sidelined for after the midfielder suffered a hamstring strain.

The 21-year-old limped off in Monday's 2-1 FA Cup quarter-final win at Manchester United and will now miss England's European qualifier against Lithuania on March 27.

Oxlade-Chamberlain, who had just returned to the first-team following a groin problem, was substituted during the second half of Monday night's FA Cup quarter-final win at Manchester United, where he had earlier set up Nacho Monreal's opening goal.

Arsenal manager Arsene Wenger confirmed the midfielder was set for a scan but the prognosis would not be determined until later in the week, although it is unlikely Oxlade-Chamberlain will feature in Saturday's Premier League game against West Ham.

Wenger said: "Chamberlain has a hamstring strain, the only thing we don't know is how bad it is because usually the scans are only done 48 hours after the accident. That will be done today"

Wenger added midfielder Jack Wilshere was "progressing well" following minor surgery to remove studs from pins in his ankle, and Mathieu Flamini had resumed full training after a hamstring problem, and will come into contention for Saturday.

There was also positive news on centre-back Gabriel Paulista, who limped off against QPR with a hamstring strain but is expected back training "on Sunday or Monday".

The Gunners boss insists recent performances have drained his squad physically, and he will have some decisions to make as he looks to keep the players fresh for both the West Ham match and the second leg of their Champions League tie at Monaco, where Arsenal will be out to overturn a 3-1 deficit.

Theo Walcott could come back into contention, having again been left on the bench at United.

"We were at a high level of fatigue because we played against Monaco, Everton, QPR, Manchester United, all very physical games," said Wenger.

"I will have to test medically, physically, how the players are on Friday, and I will make my decision then. The big priority is of course West Ham."