Mourinho frequently played down his side's chances in the 2013-14 title race, saying that they were a little horse, but now he believes otherwise.
Mourinho said that Chelsea has bought some key players and they believe that they are title contenders.
Spain striker Costa moved to Stamford Bridge from La Liga champions Atletico Madrid, while former Arsenal midfielder Fabregas joined from Barcelona.
The Chelsea boss, while saying that his summer transfers added a new dimension, said that they are a title contender. Mourinho added that if one wants me to say they would win the league he cannot, because he respects this competition.