Rob Holding was picked to play at Manchester City on Saturday - but didn't start the game.
The centre back felt a tightness in his hamstring during the warm-up and his place was taken by David Luiz.
After the game, Mikel Arteta gave an update.
"We don’t know [how bad it is]," he said.
"But it was bad enough to make the decision to get Rob out of the game and to get David in.
"David was really focused, he came on and I think he had a really good game."
Copyright 2024 The Arsenal Football Club Limited. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source.
