Leeds United defender Gaetano Berardi returned from injury on Monday night for the Whites Under-23s side as he saw action for the first time in nearly four months.
Berardi though saw his comeback cut short in the 44th minute of the game against Southampton in the Premier League Cup tie as he left the field prematurely to be replaced by Jamie Shackleton just before the break.
The 30-year-old could be seen hitting the dugout in frustration in what looked to be a disappointing end to his evening.
He was able to walk without a limp to the tunnel at the half-time whistle before he was joined by Head of Medicine and Performance Rob Price for assessment.
Leeds have confirmed that they are hoping it will be a minor setback but will confirm the extent of the issue on Tuesday.
Berardi suffered a hamstring tendon rupture in United's 2-0 home victory over Ipswich Town in late October and was subsequently ruled out for 16 weeks after consulting specialists over the issue.
United chose not to opt for surgery preferring the defender to undergo an intense rehab programme at Thorp Arch.
Berardi was among a number of first-team players made available for the fixture with new signing Kiko Casilla making his debut for the club following his acquisition from Real Madrid last week.
Whites loanee Izzy Brown also stepped up his comeback following his Professional Development League double against Crewe Alexandra at Thorp Arch last week.
The 22-year-old completed 45 minutes at the i2i Stadium as he pushes to make his long-awaited senior debut for the club having joined on a season-long loan from Chelsea last summer.
United claimed a 3-2 victory with goals from Aapo Halme, Hugo Diaz and Ryan Edmondson handing them all three points in the Group H clash.