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."
He was a player in the team that won their first European Cup at the old Wembley in 1992 and has now guided them to their third and fourth triumphs, both coming with final victories over United.
As dignified in victory as in his rare defeats, he was all modesty again after goals from Pedro, Lionel Messi and David Villa sweep United aside in one of the all-time great final performances.
"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.
EMOTIONAL TOLL
Yet Guardiola has often spoken of the emotional toll taken on the man tasked with leading a team who symbolise the whole notion of a separate Catalan nation.
The rows with Jose Mourinho and subsequent antics of the players on both sides in the semi-final victory over Real Madrid did not sit well with him and it was noticeable how much more comfortable he was pitting his wits against Ferguson in an atmosphere to total mutual respect.
Guardiola also knows that for all the plaudits raining down on his team, the concept of a total dominance of European football is something of a veneer.
His first triumph in 2009 came after his team had been frustrated by a resolute Chelsea in the semi-finals, only to sneak through on away goals after Andres Iniesta scored with their only shot on target in stoppage time of the second leg.
Mourinho's Inter also stifled Barcelona out of the competition in the semi-finals last season.
However, they were peerless in this campaign and against a United team who had not conceded a single Champions League goal away from Old Trafford, looked a class apart in the final.
Ferguson had no complaints, accepting that his side had been beaten by a team "right a
