Sky Blues development squad edged out by the Tykes at OakwellCoventry City Under 21s slipped to a narrow defeat to Barnsley at Oakwell despite twice coming back from a goal behind.
Roy O'Donovan and Jordan Willis cancelled out the Tykes' first two strikes only to be undone a third time five minutes from time.
Barnsley took the lead after 15 minutes and they could have had another from the spot seven minutes later but for a superb save from City 'keeper Lee Burge.
O'Donovan levelled the score after half an hour, latching onto a pinpoint 20-yard through ball from Louis Garner before finishing past Barnsley 'keeper Luke Steele for his fourth Under 21s goal in his last three matches.
The hosts snatched the lead back two minutes into first half injury time but City came back again on the hour when Willis headed home a corner to open his Under 21s account for the season.
Lee Carsley's side were cruelly undone though when Barnsley snatched a well-taken winner with five minutes to go.
Carsley said: "It will take time to get to grips with the Development League but there were positives from the game considering five of our players who featured were all 17 or under and playing against a side whose entire midfield has had first team experience.
"Alot of our younger players will benefit from playing with and against senior players with first team experience and they gave a very good account of themselves."