The injury to midfielder Tomas Rosicky is a major blow to Arsenal according to manager Arsene Wenger.
The Czech Republic international will be sidelined for a month because of a groin injury which comes after missing about 18 months with a similar problem and the French tactician feels for his player.
"He's devastated and I am as well," Wenger said.
"Before the Stoke match I told myself 'he has played the whole game on Wednesday, should I take the gamble or not as it was such an important game?
"But by half-time he was struggling."
Wenger admitted that players who miss so much action are likely to be more susceptible to injury when they return and had his fingers crossed that Rosicky would miss no more than a month.
"It's a vicious circle when you have been out for a long time. Eduardo had not played for 18 months, Tomas has not played for 18 months," he added.
"When you come back, one or two games, your body has to get used to producing the energy levels again and it's difficult. Nobody masters that.
"The first impression for me is that it won't be longer than a month but it's a groin problem so we have to see the scan in 48 hours which grade it is - grade one is 10 days but grade 3 is three."
