Jurrien Timber has suffered an anterior cruciate ligament injury to his right knee and will have surgery in the coming days, Arsenal have confirmed.
Timber, 22, limped off the pitch in the 50th minute of the Gunners' 2-1 victory against Nottingham Forest on Saturday.
The Netherlands international signed from Ajax for £34m last month.
In a statement, Arsenal said Timber "will be out of action for a period of time" and that they will support his recovery.
More to follow.
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