At one stage, Gary Caldwell, the Celtic captain, and goalkeeper Artur Boruc were seen grappling with one another in rage following a dangerous Hearts attack. Perhaps they were arguing over who deserved the biggest wage rise, but if performance-related pay was applicable yesterday then Hearts' youngsters would have left the stadium just as quids in as their opponents.
Hearts scored first, threatened periodically and then held out virtually until the game's last kick. They were entitled to feel aggrieved at the final outcome.
Csaba Laszlo certainly did. He pinpointed errors in the lead-up to both Celtic goals as the reasons for defeat and implored his youthful charges to learn from their mistakes.
Teenagers like the outstanding Craig Thomson and Arvydas Novikovas trooped off at the end, followed by colleagues like Lee Wallace and Suso, who are just a few years older. Winger Andy Driver, himself just 21, had already been withdrawn. Their youthful exuberance was tamed on the day but their brave performances confirmed there is much more to come.
"I am disappointed to lose in the last second, especially when we had the game in our hands," lamented Laszlo.
"I have a young squad that is looking to be better and better. Their mistakes will stop. We lost the game ourselves. Lee Wallace was 100 per cent sure this was not a corner and he let the ball go out for a goal kick.
"I must be proud about the team and the performance. I don't know how many minutes we were in front but we had some other goal chances. I am not unhappy."
"It is a disappointing to have the same situation as we had against St Johnstone in the last minute, and against Rangers at home with a penalty in the last minute. We must concentrate more in this direction. It is not usual to lose every game in extra-time," he said, before commenting on exactly why referee Dougie McDonald added four minutes of stoppage time at the end of a second half which contained just two substitutions and no injuries.
As those inexperienced young Hearts players become older, wiser and stronger, it will be intriguing to see how they match up to the Old Firm over the coming months.