The ex-Real Madrid boss lavished praise on former rival Pep Guardiola for the way he has improved on the side Louis van Gaal and Jupp Heynckes built
The Bavarians annihilated everyone in their path last season, winning the Champions League, Bundesliga title and DFB-Pokal before Jupp Heynckes stepped aside for the ex-Barcelona boss to take the helm in the summer.
Nine months on, Bayern sit top of the German league by an eye-watering 20 points, have one foot in the last eight of Europe at Arsenal's expense and have a domestic cup semi-final to look forward to.
Mourinho, who tussled with Guardiola for two seasons in La Liga when he coached Real Madrid, thinks that die Roten have improved even more under his tutelage, though he credited former bosses Louis van Gaal and Jupp Heynckes for getting the ball rolling at the Allianz Arena.
"I think Bayern are getting better and better," the coach told Yahoo. "I think this new Bayern started with Louis van Gaal.
"He started cleaning the team of all the players and starting with Thomas Muller, Bastian Schweinsteiger, Holger Badstuber and Toni Kroos, he was starting with these people and took the team to the Champions League final in 2010.
"After that came Jupp Heynckes, who did unbelievable work, and the team kept becoming better and better and they won the Champions League, and now Guardiola also is a fantastic coach and I think [they are] naturally improving. Over the last few years as a club they are doing very well."
If Chelsea beat or draw 0-0 with Galatasaray in their Champions League last-16 second leg later this month then they could face the Bavarians in the quarter-finals should Guardiola guide his players past Arsenal with their current 2-0 advantage.