Arsenal duo Mikel Arteta and Mathieu Debuchy are both expected to be sidelined for around three months, the club have announced.

Both players have undergone surgery, with Arteta recovering from an ankle injury and Debuchy struggling with a problem to his right shoulder.

Arteta has not played for the Gunners since November 26, when he came off with a calf injury during a 2-0 win over Borussia Dortmund in the Champions League.

The 32-year-old was expected to be out for three to four weeks but a subsequent problem with his ankle means rehabilitation will take "approximately three months".

"Mikel has had surgery which went well. I have just seen him, he is back with us at the training ground," Arsenal manager Arsene Wenger told the official club website.

"He had a limited mobility in his ankle and some persistent inflammation that had an impact on his calf.

"That meant we had to make the decision to have surgery and it's a proper solution which gives him the best chance to recover."

Debuchy has made only nine league starts since joining Arsenal from Newcastle in the summer.

It is the French full-back's second major setback of the season after he missed three months earlier in the campaign following ankle-ligament surgery in September.

Wenger said: "Mathieu had a surgery on his right shoulder following the injury on Sunday.

"It's very unfortunate for Mathieu, it's unbelievable because he's had two surgeries in the same season.

"He just came back, he played seven games and he's out again. I count three months out for Mathieu because contact will be a problem for the shoulder."

Arsenal's injury woes continue to mount with Jack Wilshere (ankle), Kieran Gibbs (ankle), Danny Welbeck (thigh) and Abou Diaby (calf) all missing recent matches, while Calum Chambers has been struggling with illness.

Wenger insists Welbeck will not return, as the Gunners had hoped, for Sunday's trip to Manchester City in the Barclays Premier League but there was better news regarding Gibbs.

"Kieran Gibbs will be training again with the squad on Friday and we will see how he goes from there. His news is positive," Wenger said.

"Danny Welbeck is not ready yet, he is still feeling some pain, so we will have to be patient."

Wenger will be hoping for an improvement on last season's 6-3 hammering at the Etihad Stadium as the Gunners look to close the gap on fourth place.

Arsenal's lengthy injury list may also accelerate Wenger's activity in the January transfer window.

Legia Warsaw have announced their 17-year-old midfielder Krystian Bielik will have a medical with the Gunners on Friday.

Bielik broke into the Legia first-team this season but has only made six appearances for the Polish side.

"I'm going to London to fulfil my dreams," Bielik told Legia's official club website.

"I hope I will become an Arsenal player soon."