Jack Wilshere Arsenal Luke Shaw Manchester United
Arsenal midfielder Jack Wilshere (L) could be out for a considerable time with an ankle injuryReuters

Jack Wilshere just cannot seem to catch a break. Looking good and high on confidence after some good performances, particularly in an England shirt, Wilshere would have been hoping to kick on and inspire Arsenal to a great season, but that injury bogeyman has come to haunt the midfielder again.

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After picking up an ankle injury during the English Premier League game against Manchester United, Arsene Wenger confirmed ligament damage, with Wilshere's exact timeframe on the sidelines set to be determined once he consults a specialist.

In a good case scenario, Wilshere could be back after two-three weeks, or even a month, but in a bad case scenario, the midfielder faces up to four months out, that is if he has to have surgery on his left ankle, which was injured following an awkward challenge from Paddy McNair.

"On Jack I cannot give you any time schedule," said Arsenal manager Arsene Wenger. "He will be out a while. He must see a specialist next week to see how long he will be out.

"He has a big ankle sprain and I don't want to talk about it because I'm not a specialist medically.

"The first news is they have told us that he will be out for the next few games. For how long, we will need to see a specialist."

It is the unfortunate tale of Wilshere (and a lot of other Arsenal players, it must be said) with the midfielder, when he looks like being even remotely near his best, going down with injury, be that a minor niggle or a more serious one.

"It is so sad because he just came back and had found his mobility," added Wenger. "I hope it will not be surgery, just in a boot, but it will be a few weeks."

In other injury news, Wenger also confirmed Theo Walcott will not be in the squad to face Borussia Dortmund in their Champions League game on Wednesday, with the same groin problem which kept him out of the English Premier League match against Manchester United.

Wojciech Szczesny is another casualty from the Manchester United game, with the goalkeeper ruled out with a dead leg, which means Emiliano Martinez will be in between the sticks against Borussia Dortmund.

Danny Welbeck, while not ruled out, is a doubt, with Wenger set to make a decision a little while prior to the match.

"Welbeck is in the squad, but I don't know [if he will play], I have not decided yet," said Wenger.

With Olivier Giroud not registered by Arsenal to play in the group stages, it does reduce the options for Wenger in terms of using a traditional centre-forward.

There is some good news for Arsenal on the injury front, however, with central defender Laurent Koscielny set to make a return after a month and a half out with an Achilles problem.

"He's in the squad for tomorrow," said Wenger on Tuesday. "It's very good news because he was out for a while now and we are short in numbers defensively. It's good to have his quality back."