Mourinho's men are well on course to be crowned champions of England for the fifth time in the club's history and first since 2009-10.
But Mourinho is wary of getting carried away as Chelsea prepare to travel to relegation-threatened QPR on Sunday for the first of their remaining eight league matches.
When asked who are his side's biggest threat in the title run-in, he replied: "All of them.
"Mathematically it is open. Every team with less than 21 points distance to us mathematically is in the race.
"Being objective, a team with seven, eight, nine points difference is obviously still in the race."
QPR, who are third bottom, have picked up four points from their last two games as they scrap for top-flight survival.
Mourinho added: "We need points, we need victories and we cannot choose matches. It doesn’t make any sense to think about some matches and not others.
"Obviously it's very important for both teams. Nobody is expecting an easy match.
"Last weekend we played against a team that is very stable in the middle of the table [a 2-1 win over Stoke City] and they were fantastic in their approach, their commitment, trying to win the match or not losing it.
"Everybody knows they [QPR] need points in the remaining six fixtures they have, so we know it will be a difficult game for us.
"It's a three-point match and we have to play with our maximum to try to get them."
