The 40-year-old has only been in charge for three seasons but such is the mental strain of being at the helm of an institution that is so much more than a football club, that he is contemplating walking away after one more year at the helm.
Indeed, after Saturday's 3-1 Wembley defeat it was United's evergreen 69-year-old year old boss Sir Alex Ferguson, in charge for 25 years, who was already planning how to build a team to challenge the Spaniards for top European billing.
Guardiola is steeped in Barcelona history and never misses an opportunity to remind people that he is a "mere cog in the machine."
"I feel privileged to have these players, I don't feel like the boss of them," he said after Saturday's triumph. "So many people have worked so hard to achieve this and I congratulate everyone.
"I'm so happy to be here as a coach of these guys. I intend to continue one more year and we'll see.
"The challenge has to come from inside myself. When the passion of the night has gone I'll go home, rest a bit and come back."
It might seem extraordinary that such a young, fresh and wildly successful manager could consider walking away from one of the greatest teams ever to play the game, when the prospect of hauling the club closer to Real Madrid's daunting tally of nine European Cups is right there in front of him.
Mourinho's Inter also stifled Barcelona out of the competition in the semi-finals last season.
Ferguson had no complaints, accepting that his side had been beaten by a team "right a
