Nicola Pearson, BBC Sport
Amid the expectation and optimism of fans to see their new signing on the Premier League stage, Jurrien Timber had his debut cut short on Saturday to what looked like an innocuous injury at the time.
On Wednesday it was confirmed the defender suffered an ACL injury requiring surgery and that he will be out for a lengthy period of time.
The versatile 22-year-old was brought in to provide depth and competition to the side after injuries halted Arsenal’s momentum in the title race last season.
So how much will he be missed by the Gunners and who will replace him?