Guardiola was ripped for his decision to leave Germany star
Thomas Mueller and French winger Franck Ribery on the bench at the start of the match.
Die Welt described the exclusion of Mueller and Ribery as like "an own goal" for Bayern. Kicker magazine said it was "risky and wrong" to overlook Mueller, while the headline in the tabloid Bild was "Super solo from Atletico! Poor selection from Pep."
Bayern had no answer for Saul's spectacular goal in the first half even after Guardiola finally brought on Mueller and Ribery for Kingsley Coman and Thiago Alcantara.
The decision to not start Mueller was the biggest surprise. He came into the game with 31 goals, including eight in eight starts in the Champions League, and was Bayern's leading scorer on the road in the Champions League.
But Kicker also pointed out that Ribery, out for the first four months of the season, was "shining again after a long absence" and could have been "the man for the occasion" in Madrid.
Guardiola explained his decision by saying that he wanted a left-footed player on the left and a right-footed player on the right and to have an extra midfielder, Thiago in place of Mueller.
Bayern has exited to Barcelona and Real Madrid in the last two years after failing to score in the away game. Will the same thing happen against Atletico in 2016?
imagine that Guardiola would not start Mueller next Tuesday, but he is keeping the decision close to his vest.
"There may be another choice in the next match," said Guardiola of the Bayern lineup for the second leg at the Allianz Arena on Tuesday.