Soccer often throws up surprises and one at the weekend in the Bundesliga was no exception. Tongues will wag and an inquest will be opened after Bayern Munich were left shell shocked after losing 2-0 at home to Borussia Mochengladbach.

It was only Bayern’s second defeat of the season, and Arjen Robben’s return was soured by yet another injury after tearing a stomach muscle and is set to miss at least two weeks.

So in asking why Bayern lost we could connect manager Pep Guardiola’s midweek trip to see his old club Barcelona. Guardiola was there sat next to his father to watch Barcelona’s sizzling 1-0 victory over Manchester City.

It was Guardiola’s first return to the stadium to watch a fixture in three years, so instead of taking up a VIP seat, he used his season ticket and sat with fans.

Guardiola simply could not hide his emotions, moving in his chair, smiling and looking stunned with excitement when Lionel Messi on more than one occasion nutmegged the opposition. It was a special show and Guardiola enjoyed every minute.

On the surface there seems little wrong with an ex-manager watching his former club, a team he also played for and perhaps picking up notes about them – if Bayern are due to face them later this season.

However, Guardiola clearly wasn’t at the Nou Camp for this reason or if he was that was soon vanquished when Messi and his team put on an impressive display in front of a sold out home crowd.

For 90 minutes he ceased to be the manager of Bayern Munich and became a fan of Barcelona. And if you weren’t a Bayern fan it was simply heartwarming to see.

Considering his association with the club this seems normal, apart from the fact that he was cheering on a club that are in the same competition as his own.

Had this been a quick trip over to Spain to watch a league match or perhaps a cup match there could be no complaints. But here was Guardiola showing his true emotions for a club that before the quarter-finals draw was made he could have been playing in three weeks time.

Three days later, Bayern hosted Moechengladbach a game they were expected to breeze through and lost to a team that could have been backed at 16/1 to win.

Bayern of course will recover from this. Title rivals Wolfsburg could only draw at the weekend meaning that the champions have a 10-point gap at the top of the Bundesliga.

At least for Bayern’s hierarchy, Guardiola will not be able to repeat the same feat for the quarter-finals of the Champions League. Bayern, who play FC Porto, will be playing on the same night as Barcelona.