Gabriel Jesus was not present in Arsenal's training session on Wednesday ahead of their Europa League clash with Bodo/Glimt.
The 25-year-old summer signing was caught by a flailing arm from Liverpool full-back Kostas Tsimikas in the Gunners' 3-2 win at the weekend and appeared to be in some discomfort before leaving the pitch a few minutes later.
After the game, manager Mikel Arteta admitted he was not too concerned by the severity of Jesus' injury.
"I don’t know, I haven’t been with the doctor yet, I’m sure they are checking him, he seemed ok after the game, I don’t know actually what happened but we’ll assess how well he is," he said on Sunday.
Now, however, Jesus was not present for training on Wednesday, sparking concerns over his head injury.
Arsenal are yet to explain the reason behind Jesus' absence.
In the Europa League, Jesus is yet to start a game this season and has instead been rested while 23-year-old Eddie Nketiah gets the chance to impress, and the likelihood is that Arteta would opt to start Nketiah against Bodo/Glimt anyway.
However, with Premier League meetings against Leeds and Jesus' former employers, Manchester City, coming up in the next seven days, Arteta will undoubtedly be desperate to see his top scorer back at his best as soon as possible.
Source : 90min