Alarm bells will be ringing at the Emirates after Alexandre Lacazette limped from the field just 12 minutes into Arsenal's Emirates Cup clash with Lyon.
Lacazette took an early blow to his ankle and attempted to run it off, but was in discomfort as he was replaced by young winger Reiss Nelson.
With the Gunners' Premier League opener against Newcastle just two weeks away, Unai Emery will be praying the injury isn't too serious.