Arsenal midfielder Cesc Fabregas faces up to two weeks on the sidelines after picking up a hamstring injury.
Fabregas limped off during Arsenal's 3-1 Champions League defeat to Sevilla on Tuesday night, with reports suggesting the young Spaniard will be out for at least 10 days.
Should this be the case he will miss Arsenal's trip to Aston Villa on Saturday, the match against Newcastle four days later and possibly their third Premier League away match in a row at Middlesbrough on Sunday week.
Fabregas said: "I felt my hamstring in the first half. I kept going but I felt it again in the second half.
"It's the first time in my life I have felt this and I didn't want to take a risk."
Fabregas has been a revelation for Arsenal this season, cementing his position as one of the best midfielders in the world with a string of combative, influential displays.
Both Real Madrid and Barcelona have been linked with the 20-year-old, who has remained loyal to Arsene Wenger and believes his long-term future lies at the Emirates.
Wenger will want to get his playmaker back as soon as possible to help maintain Arsenal's title push.
They currently hold a three-point advantage at the top of the Premier League table, with a game in hand, but any further injuries to key players could see their season come off the rails.
Robin van Persie's return from a knee injury has not progressed as quickly as anticipated and the Dutchman will certainly not be fit enough to face either Villa or Newcastle
By Richard Clrke
Robin van Persie is still two or three weeks from full fitness.
The striker last played for Arsenal on October 7 when he struck twice in the 3-2 win over Sunderland at Emirates Stadium. He injured his knee in the international break that followed and has been out of action ever since.
Arsène Wenger was hopeful the 24-year-old would be back for last weekends game with Wigan. That estimation has had to be re-assessed. Now he is set to return just before the Christmas rush of games.
Van Persie is out, said Wenger ahead of Saturdays game at Aston Villa. It will be two or three more weeks.
The manager said the problem was bigger than first thought, adding: There is still pain. He is not close, he has no chance at all for next week.
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