Arsenal have confirmed that Dutch defender Jurrien Timber has sustained an injury to his anterior cruciate ligament and will undergo surgery in the coming days.
The 22-year-old - a summer signing from Ajax - was taken off the field after just 50 minutes during his Premier League debut against Nottingham Forest on Saturday.
Timber was a little bit worse for wear after colliding with Brennan Johnson towards the end of the first half, and some suspected that Mikel Arteta may have taken him off during the break.
However, Timber was surprisingly sent out for the second half, but only a few minutes after the referee's whistle had blown, the Netherlands international collapsed to the turf with nobody around him.
Timber was able to limp off the field with the assistance of medical staff, as Takehiro Tomiyasu came on for the final 40 minutes of Arsenal's 2-1 win at the Emirates.
Arteta did not have any information on Timber's injury straight after the game, but he defended his decision not to take off the full-back at half time, having been given the green light by club doctors to send him back out.
However, reports emerged earlier this week claiming that Timber's injury was as serious as feared, and Arsenal have now confirmed the worst-case scenario, as the ex-Ajax man prepares to begin the long road to recovery from ACL damage.
It is not known whether Timber suffered a full rupture, but the Gunners confirmed in a statement that he would be out for an unspecified period of time after his procedure.
"Further to detailed assessments with consultant specialists since Saturday, we can confirm that Jurrien Timber has sustained an injury to his anterior cruciate ligament in his right knee," a medical update read.
"Jurrien will undergo surgery in the coming days and will be out of action for a period of time. The support and expertise from our medical team and everyone at the club will now be focussed on Jurrien's rehabilitation programme, to ensure he recovers well and is back playing as soon as possible."
While Arsenal have not put a timeframe on Timber's recovery, the Dutchman is expected to spend several months on the sidelines, and it remains to be seen whether he will play again in the 2023-24 season.
Arsenal paid an initial £34.2m to sign Timber from Ajax, which could rise to £38.5m in performance-related add-ons, and the 22-year-old impressed at left-back in the Gunners' Community Shield success against Manchester City before starting against Forest.
The versatile Netherlands international took on an unfamiliar left-back role in the absence of Oleksandr Zinchenko, who has missed Arsenal's first two games of the new season with a calf problem.
The Ukrainian is expected to make a full recovery soon, but Arteta also has Tomiyasu, Jakub Kiwior and the out-of-favour Kieran Tierney capable of filling in on the left-hand side.
Arsenal return to Premier League action with a London derby away to Crystal Palace on Monday night.
