Liverpool's 3-2 win at Fulham on Wednesday evening put them four points behind leaders Chelsea in the table with 12 matches remaining.
The Blues - as well as second-placed Arsenal and third-placed Manchester City - all have two-legged Champions League last-16 ties coming up, whereas Liverpool only have the FA Cup as an additional distraction.
Mourinho feels this could be pivotal over the final weeks of the season, but believes there will be more twists and turns to come in the Premier League with every team fighting to win vital points.
Mourinho told Sky Sports News: "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 - it is difficult for every one of us.
"There are teams with more potential than others, obviously. There is another, like Liverpool, with a big advantage with the fact that they don't play in the Champions League.
"Playing in this is going to take concentration and energy from the teams that are involved in it.
"I think it will be good fun.
"Maybe we lost two points or won one point against West Brom and I think it will be like this until the end of the season.
"All teams need points for their objectives - some for relegation, some for the Champions League, so the fight for points will be harder."
And the Chelsea manager insists the subject of John Terry playing for his country again should not be under his discussion.
England manager Roy Hodgson this week made a concerted effort to end any talk of Blues central defender 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.
But Mourinho believes Terry's retirement from England duty will benefit Chelsea.
"It's a waste of time to keep speaking about the situation," Mourinho said.
"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."