Arsenal manager Arsene Wenger has revealed that Tomas Rosicky was left "devastated" by his recent injury blow.
The 35-year-old is expected to be out of action for another month after suffering a thigh problem at the weekend.
Rosicky had only just recovered from a knee injury when he made his first appearance of the season as a substitute in Saturday's 2-1 triumph over Burnley in the fourth round of the FA Cup.
"He's devastated," ITV News quotes Wenger as saying. "Unbelievable. Nobody understands [how he got injured]. I told him straight away after half time to warm up. I observed him, he's very conscientious Tomas, he did sprint and sprint and sprint.
"He comes on, after three minutes he got the injury. I looked at him and thought 'Tomas you do not run properly' because he didn't lift his legs and he lost some balls, I was amazed because he is top level technically.
"He told me after the game that he did it straight away, then I understood why that happened to him. He said 'I stayed on because you couldn't change anymore'. He warmed up well, for 20 minutes."
The Czech international's contract expires at the end of the season.