Mourinho's men head the table but fourth-placed Liverpool are just four points adrift.
Chelsea, second-placed Arsenal and third-placed Manchester City are all involved in Europe's premier club competition.
Although Brendan Rodgers' men are 8-1 with most bookmakers, the Portuguese thinks they have to be taken seriously because they do not have the distraction of European football.
Mourinho explained: "When I say we're not the top candidate everyone thinks 'here he is again, with what you like to call the mind games'.
"But it's just my feeling. The league is amazing but Liverpool have a big advantage because of the fact they don't play in the Champions League."
Mourinho does not expect his team or any of their rivals to have an easy run-in.
He added on Sky Sports News: "Every team needs points for their objective - some for relegation, some for Champions League football and some are trying to be champions. It's going to be hard for everybody."
England manager Roy Hodgson this week made a concerted effort to end any talk of Blues central defender John Terry coming out of international retirement.
Terry's form has been so good this year that Gary Lineker, among others, called for the Chelsea skipper to come back to the international fold.
And Mourinho does not believe the subject of Terry playing for his country should be under discussion.
He added: "It's a waste of time to keep speaking about the situation.
"Roy Hodgson is the person to kill the discussion or to feed it. End of story.
"I'd never intervene. He's in charge and has everything in his hand. He has made that decision.
"For me as a Chelsea manager I'm happy players play with their national teams - but at the same time I'm happy an important player like him is fully focused on his work at Chelsea."