The Spain midfielder has impressed in his pre-season outings for the treble-winners, but his coach is not yet satisfied with his physical condition
The Spain midfielder has impressed in his pre-season outings since joining the Bavarians in a €25 million [£21.5m] deal from Barcelona earlier this month, but his coach believes he is still physically some way behind his team-mates.
Guardiola told reporters: "We have to know that he arrived in Munich a week ago. His physical condition and movements are slower than the rest."
Goals from Philipp Lahm and Mario Mandzukic sealed victory for the treble-winners over an under strength Barca side, led for the first time by new boss Gerardo Martino, and Guardiola admitted it was a special night to face his former club.
"It was a very special day," he continued. "In all my life as a player and coach this was the first time I have faced the club.
"It was a friendly but it was a good test for the Supercopa. Barça are always a very good team. Playing against many of these players I know very well. The club is always a very difficult team."
The 44-year-old also thanked the man he has succeeded at the Allianz Arena, Jupp Heynckes, for giving him the opportunity to fight for three more trophies, with the German Supercup, Uefa Supercup and Club World Cup still up for grabs for Bayern in the early stages of the new season.
He said: "He gave me the opportunity to fight for the three remaining titles. We can only be grateful and try not to fail. The recovery will be a little tight for Saturday's game against Dortmund, but we will try to do very well."