Chelsea will aim to move within three points of the Premier League title by winning at Leicester on Wednesday night.
But Mourinho says that although he expects his team to be in the title mix next season, Chelsea???s rivals will all be able to mount strong challenges.
“At this moment, it’s very difficult in the Premier League for a team to be dominant,” he said.
“This is not Germany with Bayern (Munich). This is not Switzerland with Basle. This is not Scotland with Celtic.
“It’s even more difficult to dominate than before. How can you speak about domination when everyone knows what will happen next summer?
“Arsenal have a phenomenal squad. Thierry Henry said they need four top-class players. Give Arsenal four top-class players and I think they will again be the Invincibles.
“Man United have a phenomenal squad, including the most expensive player in the history of the Premier League (Angel di Maria), who is not playing.
“They are a club where Financial Fair Play doesn’t make a huge difference for them and they will invest hugely again in the summer.
“Man City have done phenomenally, winning two titles in three years, and people say they will invest hugely.
“Liverpool fighting for the title for many years. So next year it will be even more difficult for everyone than this year.”
Whether Didier Drogba will be at Stamford Bridge to meet the challenge next season remains unclear.
The veteran striker???s contract ends this summer, and Mourinho says that the decision on Drogba???s future is likely to be made not by him, but owner Roman Abramovich.
“I didn’t speak with him (Abramovich),” Mourinho said. “I think it belongs to him: what he feels, what he thinks.
“This is a club thing. This is a Mr Abramovich thing. Mr Abramovich wants him to do what he wants in the club, but it’s something Mr Abramovich has to tell him.
“He has to decide. But, obviously, he belongs to the history of this club. These guys are special players.”
Mourinho believes John Terry, Drogba, Petr Cech and John Obi Mikel will bridge a generational divide if, as expected, they win the title, a decade on from their first, in the Portuguese’s first season.
“It’s nice to belong to two different generations,” Mourinho said.
“The same as me. It’s nice to belong to the history of a club in different moments. If you manage to be champions, it’s very nice for these older guys.”
Asked how such influential players can be replaced, Mourinho pointed to the example of Frank Lampard, the club’s record goalscorer who left last summer.
“Chelsea lost, in the end of last year, what I consider, for sure, one of the five most important players in the history of Chelsea FC: Frank Lampard,” Mourinho said.
“We lost that player. But life goes on. You have to think about the future and to build.
“(Branislav) Ivanovic is experienced. (Cesar) Azpilicueta gets experience. (Eden) Hazard is here for three years.
“(Nemanja) Matic gets experience. The years are for everyone, not just for them. Ruben Loftus-Cheek is 18 and he just arrived. In five years’ time he will be 23, so I see this as a natural process.”