Manchester United midfielder Paul Pogba endured a captaincy debut to forget as he suffered an early hamstring injury.
The 24 year-old was handed the United armband for the first time for his side's 3-0 UEFA Champions League Group A win over Basel.
Yet his spell on the field lasted a mere 19 minutes, with Pogba forced off after feeling his right hamstring.
The France international has been in superb form for United this term, netting twice in the opening fives games.
Any prolonged absence, therefore, would represent a significant blow as a packed fixture list awaits now that European football has returned.
United, unbeaten after four Premier League fixtures, hosts Everton at Old Trafford on Monday (AEST).