Arsenal will have to wait for a little longer to learn the extent of Rob Holding's injury, which he picked just before their match against Manchester City on Saturday.
The defender was named in the starting lineup to face City at Etihad but picked a hamstring injury during routine warm-up before the match.
Speaking after the game, Arteta said 'it was bad enough', but was not certain how long he could be out.
"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."
His injury is a blow to coach Arteta and Arsenal, even though they are not short of options at the back with the likes of Luiz and Gabriel Magalhaes available.
In addition, Cedric Soares and Pablo Mari are expected back from injury, which means the Gunners have enough cover ahead of a busy schedule.