The English Premier League club have already qualified for the knockout stages and will qualify at the head of Group E if they beat Steaua Bucharest at Stamford Bridge in their final group game.
That will move Chelsea manager Mourinho one step closer to becoming the first manager to win the competition with three different clubs having lifted the trophy with Porto and Inter Milan.
But the Portuguese manager insists Bayern Munich, Barcelona and Real Madrid are the leading contenders this season with his own club one of a number who he considers to be outsiders.
"I think our chances, this season, which is my first season, are not comparable with the chances other clubs have," Mourinho said.
"I think other clubs have completely different stability, squads, evolution of the team to be considered the favourites to win the competition.
"We have reached the last 16. If we reach the quarter-final, which is the next step, every team in the quarter-final has a chance to win it.
"But in my analysis, I think we are not considered one of the favourites to win the competition.
"In my opinion, my favourites are Bayern - European champions and a top club, with the same players and a new manager, same team and unbelievable stability.
"They won it last year, were in the final the year before, in a final in 2010. Fantastic stability in this level. Barcelona. Real Madrid. And these three teams are, clearly in terms of potential and responsibilities, in front."
Mourinho added: "But I could say other teams are very strong. And one of these teams arrive in the last eight, anything can happen. These teams are obviously Manchester City, Man United, Atletico Madrid, Chelsea... there is a group of teams that arrive in there.
"But we are still in the first phase. The last 16, we will find some difficult matches because some important teams will finish second."
Chelsea will face Steaua on the back of a 3-2 Premier League defeat at Stoke City and having conceded six goals in their last two games.
In addition, the club's three strikers - Fernando Torres, Samuel Eto'o and Demba Ba - have scored just four Premier League goals between them.
But while Mourinho admits his side is a work in progress, he insists he will not change the team's style of play.
"The most difficult thing in football is to play the way we are playing. It's much more difficult to play offensive, creative, dynamic football. The easiest thing in football is to play defensively," he said.
"We have to score goals. You can say we scored two away and lost. I know. Because at the same time we are also conceding goals defensively.
"Maybe you'll laugh but, if we trained defensive corners against the dummies at the moment, maybe they would score. All the rebounds are going in.
"We are creating a lot. We have to score goals and kill off opponents. If we don't do that, we have to be very safe at the back.
"Am I going to change the style and play a more defensive style? No."