Mourinho says Bayern always have an advantage in Europe because they dominate their domestic league.
He told France Football: "The English clubs are economically so strong that the market is open to all. Take, for example, the Bavarians in Germany. Do you know when winning the championship starts for them every year?
"So, the summer before, they buy the best player of Borussia Dortmund. Götze, then Lewandowski the next year and Hummels last year.
"I have come to a club with a great and prestigious history. However, this cannot simply be carried on in this way. No club in England, be it Manchester United, Liverpool or Manchester City can permanently dominate the league. The resources are distributed. Everything is much more complicated: shopping, winning, building something."