Arsenal manager Mikel Arteta has admitted that Reiss Nelson's injury in the Gunners' 2-0 friendly defeat to Juventus on Saturday is "not good news".
The 23-year-old began the match against an inexperienced Bianconeri XI but lasted just over 20 minutes before pulling up with an apparent leg injury.
Nelson was pictured feeling the back of his thigh and was soon taken off to be replaced by Marquinhos, as Arsenal slumped to a disappointing loss in front of their own fans.
Own goals from Granit Xhaka and Rob Holding in first and second-half injury time settled the contest in Juve's favour, and Arteta was immediately asked about the extent of Nelson's injury after the match.
The severity of the attacker's issue is currently unclear, but Arteta cut a pessimistic figure in his post-game press conference, telling reporters: "We don't know the extent of the injury.
"The fact he had to leave the pitch immediately is not good news, especially someone like Reiss, who is really powerful and fast. Let's see what happens."
Nelson has only made seven appearances in all tournaments this season after sustaining a serious quadriceps injury in pre-season, but he has come up with a respectable two goals and two assists in that time.
When asked if the Englishman's injury could impact Arsenal's strategy for the January transfer window, Arteta responded: "We know what we have to do and that hasn't changed the plans."
Nelson joins an ever-growing list of Arsenal absentees, with Gabriel Jesus out for the long-term after undergoing knee surgery and Emile Smith Rowe still recovering from a groin operation.
Furthermore, none of Takehiro Tomiyasu, Oleksandr Zinchenko or Albert Sambi Lokonga could take part in Saturday's game due to various knocks, while Bukayo Saka and Gabriel Martinelli were still absent following their World Cup quarter-final exits.
However, Arteta was able to offer a more positive update on Smith Rowe, Tomiyasu and Zinchenko as Arsenal gear up for a return to Premier League action against West Ham United on Boxing Day.
"[Emile] hasn't been able to train in the last few days but hopefully he can start [to train] next week. He's been out for a while now - he needs some time to get back to speed," Arteta added.
"We really need him and we're going to welcome him with both arms, because he's a really important player for us. We need him fit on the pitch. Alex is progressing well and Tomi is running on the pitch.
"Hopefully we're going to get the international players [who have been at the World Cup] joining again this week and then we'll all be watching William Saliba tomorrow to see if he can win the World Cup."
Arsenal resume top-flight duties sitting five points clear of Manchester City at the top of the table and will be sitting at the summit on Christmas Day for the first time since the 2007-08 campaign. body check tags ::
