I am concerned because he hasn't had many muscular issues and he had to leave the pitch and he was feeling something, That's obviously never a good sign, especially for a player that is very, very explosive. So we are digging in a little bit more to understand where we are in terms of the injury and we'll announce the moment we know. He's definitely not available [to play Slavia]. He hasn't trained today. We need to do some more tests and scans in the next few days to understand the extent of the injury.
"No, he's definitely not available," said Arteta when asked by BBC Sport if Gyokeres was in the squad. "He hasn't trained today. We need to do some more tests and scans in the next few days to understand the extent of the injury. But he's not available."