Alex Oxlade-Chamberlain
Alex Oxlade-Chamberlain has been ruled out for up to four weeks with an hamstring injury picked up during Arsenal\'s win over Manchester United in the FA Cup Reuters

Arsenal have suffered a major blow as midfielder Alex Oxlade-Chamberlain could reportedly be ruled out for up to four weeks with a hamstring injury.

According to the Daily Mail, the midfielder, who limped off 50 minutes into the FA Cup game against Manchester United, which the Gunners won, has undergone a scan on Tuesday, but the club medical staff are waiting more tests before revealing the exact prognosis of the injury.

Oxlade-Chamberlain, who played a key role in Arsenal's first goal against United in their FA Cup clash was close to reaching his best form of the season. The midfielder has been impressive for the north London club this season, and has managed to overtake Theo Walcott in the running for a place in the starting XI.

The midfielder's latest injury could see him miss crucial clashes for club and country. The former Southampton player is a big doubt for England's Euro 2016 qualifier against Lithuania and friendly against Italy later in the month and could also miss out on Arsenal's Champions League clash against Monaco next week and Liverpool's visit to the Emirates Stadium in April.

This news will come as a blow to Arsene Wenger, who is a big admirer of the midfielder. But the Frenchman will be compensated by the imminent return of Jack Wilshere, and the availability of Theo Walcott, who has been used sparingly by the manager in recent weeks.

Meanwhile, defender Nacho Monreal has praised the team following their win against United and believes that the team now has the mentality to cope with the big games.

"Everyone had memories of last season that we lost all the games against top teams," Monreal said, as quoted by the Mirror.

"This season we played really well against City, we won and it was fair and it was the same against United. We played really well and are very happy for the victory."

"We are in a good dynamic in the last few games. Except for Monaco when we didn't play really well, in the rest of the games we have played well and won most of them. This is the style now we have to keep going," the Spanish international defender added.