Bukayo Saka left the pitch with an injury in the 53rd minute during Arsenal's clash with Leeds on Saturday afternoon, leaving Mikel Arteta with a looming concern ahead of his side's trip to Anfield next weekend.
Saka went down moments after the hosts scored their third goal against the visitors, courtesy of blockbuster summer signing Viktor Gyokeres.
The England international pulled up on the pitch and was briefly attended to by medical staff, before signaling to his manager that he would need to be replaced.
Before exiting the field, Saka had scored Arsenal's second, with the Gunners in cruise control thanks to a 4-0 lead in the second-half at the Emirates.