The Netherlands winger admits that he expected the former Barcelona boss to head to England but adds that his arrival in the summer can only be a positive step for the Bavarians
Die Roten announced earlier this week that Guardiola would replace current coach Jupp Heynckes at the end of the season, ending speculation that the Spanish trainer might head to the Premier League after his sabbatical.
The move caught many unawares and Robben revealed that he was no exception when he spoke to reporters after Bayern's 2-0 win over Greuther Furth.
"I was surprised, also because it happened really quickly," said the 28-year-old Dutchman.
"One day before he signed I read that he was looking forward to working in the Premier League. A day later he signed at Bayern. It was surprising but good."
Bayern currently lead the Bundesliga by nine points from second-placed Bayer Leverkusen and several of Robben's team-mates, such as defender Daniel van Buyten, have stressed the team need to avoid being distracted by the news.
"We are proud, because he [Guardiola] is one of the best, maybe the best coach and he chose the best club," stated the Belgian.
"But this is in the future. Now we want to deliver a good second half of the season. We do not want to speak a lot about the future.''
This was a sentiment endorsed by Thomas Muller, who also stressed caution against over-optimism:
"Everyone says that Guardiola is good for the Bundesliga and FC Bayern," the Germany forward told journalists.
"But nobody knows how good the results will be."
The Bavarians have 45 points from their 18 league fixtures this campaign.