Barnet are waiting to discover the extent of the injury suffered by Collins John against Plymouth on Saturday.
The former Fulham striker had to wait a fortnight to make his debut for the Bees due to a delay in receiving international clearance.
But his eagerly-anticipated first appearance in a Barnet shirt lasted just 15 minutes before he was forced off with a quad injury.
The 26-year-old could now be a doubt for the Bees' next game, on Friday evening at home to Northampton.
Barnet's misery was compounded by a 4-1 defeat by Argyle on the day Collins' fellow Dutchman Edgar Davids made his bow in the dug-out as the club's new head coach.