Arsenal midfielder Jack Wilshere has suffered a stress fracture in his right foot during his recovery from an injury sustained in pre-season.
The England international had surgery in September on an ankle injury and had hoped to return in February.
But the club have confirmed Wilshere, 20, has suffered a foot fracture but is not expected to miss the rest of the season.
Wilshere has not played since England's 2-2 draw with Switzerland in June 2011.
Jack Wilshere factfile
- Born on 1 January 1992
- Joined Arsenal in October 2001
- Made senior debut against Blackburn as a substitute in a 4-0 victory
- Scored first Arsenal goal versus Sheffield United in a Carling Cup tie
- Spent second half of 2009-2010 season on loan at Bolton
- Makes England debut versus Hungary in August 2010
- Arsenal's most-used player in 2010-2011 season
"I can confirm I have a stress fracture but it is not in the same area as my first injury which has healed very well which I am happy about," revealed
Wilshere on his Twitter account
"I have developed a stress fracture in the heel now and I do not want to put any time scale on it as I do not know how long it will take."
The club confirmed: "This is a recognised complication of a complex rehabilitation process and, of critical importance, Jack's initial injury is recovering well."
Last Friday Gunners manager Arsene Wenger revealed Wilshere "felt pain again in his ankle" while running, and was to see a specialist on Friday.
Wenger said on Friday: "I am so sad that at that age you have to be out for such a long time with not any obvious reason.
"If you had told me that Jack would not have played one game by February, I would have said 'that is impossible'.
"We miss that little burst from Jack. Let's hope it goes well and we have good news from the specialists."
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The Arsenal boss is expected to discuss the news of the fracture after his side's clash away at Bolton on Wednesday.
Wilshere sustained the original injury, which was later diagnosed as a stress fracture to his right ankle, in a pre-season friendly against New York Red Bulls on 31 July.
It was first hoped it would heal with the help of a protective boot, but he was forced to undergo an operation.
In December, Wenger said Wilshere had an "exceptionally good" scan, but the latest news comes as a blow as the Gunners chase a top-four finish in the Premier League and look to progress in the Champions League.
However, Wilshere has picked up this latest injury while undergoing his rehabilitation.
With the club revealing the midfielder will not miss the rest of the season, England manager Fabio Capello will be hopeful he is fit for Euro 2012 in the summer.