Jack Wilshere will be sidelined for three to four weeks with fresh injury problems, dealing a blow to Arsenal and England ahead of key games.
The 21-year-old midfielder, who missed the whole of last season, is out of Arsenal's Champions League decider at Bayern Munich on Wednesday as well as two World Cup qualifiers for England.
Arsenal manager Arsene Wenger said Tuesday that Wilshere has an inflamed left ankle after being injured in the Premier League game against Tottenham on March 3.
A right ankle injury kept Wilshere out of action from July 2011 to October 2012, and Wenger wants to ensure he is rested to prevent another lengthy layoff this time.
"I could see in the last couple of games he had started to dig deep,'' Wenger said. "He has played 30 games. For us it is not welcome but maybe for him it is not bad that he has a little breather.''
Wenger said the "initial plan'' is for Wilshere to be out for three to four weeks.
"It is more about prevention,'' Wenger said. "The specialist decided he needed it. He has some bone bruising. The last time it deteriorated into a stress fracture. That's what we don't want to happen.''
Wilshere will be missing in Munich as Arsenal tries to overturn a deficit in their last-16 Champions League encounter on Wednesday.
Arsenal is currently fifth in the Premier League - one place below the Champions League qualification places - and will be without Wilshere in Saturday's match at Swansea.
"He was out for 17 months and we had to deal with it,'' Wenger said. "We must be able to deal with it for two or three games.''
Wilshere will be a big loss for England later this month, with a trip to San Marino followed by a tough match at Montenegro, which tops the qualification group.