Arsenal star Jack Wilshere is expected to miss the upcoming Premier League trip to Bournemouth on Sunday, 14 January, after suffering an ankle sprain during Wednesday's goalless draw at Chelsea in the Carabao Cup semi-final first leg.
The 26-year-old midfielder started in the middle of the park alongside Granit Xhaka after having returned to form in recent weeks.
However, he was forced off and replaced by Mohamed Elneny in the 57th minute of the game after twisting his ankle while attempting to block a pass from Chelsea's Danny Drinkwater.
Arsene Wenger confirmed the blow after the game but the Arsenal boss is hopeful the midfielder would be back soon.
"He has an ankle sprain and the first look at it was not too bad, but of course, for Sunday [against Bournemouth], I think he will be short," Wenger confirmed in the press conference following the draw at Chelsea.
"I do not know how long he will be out. It is a shame to lose him when he is in such good form and it was by blocking the shot that turned his ankle and it's his good ankle, so I am quite positive."
Arsenal are about to lose another midfielder with Wenger confirming that Francis Coquelin is set to join Valencia.
The France midfielder has only started one Premier League game so far during the first half of the season and Wenger has agreed to sanction his departure in a deal said to be worth around £12m.
"He goes to Valencia. He didn't get enough games with us this season, he had an opportunity and I let him go," Wenger admitted after Coquelin didn't even make the bench for the game against Chelsea.
The Frenchman's departure would be Arsenal's second deal of the January transfer window following the arrival of Konstantinos Mavropanos from Greek side PAS Giannina.
Questioned about whether he also plans to sign a new midfielder to fill Coquelin's gap, Wenger said, "First of all, the best way to replace him is to get Aaron Ramsey back and Mesut Ozil back. That will help.
"After that, we will see. We saw again Maitland-Niles had an outstanding performance tonight. He's a defensive midfielder basically, so at some stage, I play him in there. We have Kolasinac injured, Monreal injured – but they will come back. So that is an opening for him."