As the Blues close in on the Premier League title, Mourinho made it clear that English football is almost impossible to dominate due to the fact that the top echelon of clubs have the propensity to spend money to improve their playing groups.
One team who will benefit from a summer influx are the Gunners who according to the Chelsea boss can quite possible return to their halcyon days of over a decade ago when they went through the 2003/04 season undefeated.
"It's even more difficult to dominate than before," the Chelsea manager said.
"How can you speak about domination when everyone knows what will happen next summer?
"Give to Arsenal four top-class players and I think they will again be the Invincibles.
"Man United have a phenomenal squad. They will invest hugely again in the summer. 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. Next year it will be even more difficult for everyone.