The Blues went top of the table yesterday after a comfortable home win against Newcastle, on the same day that title rivals Arsenal and Manchester City both failed to win.
Mourinho has played down talk of his side winning the league in the media, but behind closed doors the Portuguese maestro told his players that they will win the league.
After a disappoint draw at home to West Ham, Chelsea have impressed with wins against Manchester City and Newcastle.
The Blues face Arsenal, Tottenham and Everton before the end of March as well as big games in the Champions League and FA Cup but Mourinho remains confident.
A Daily Mirror source said: “Jose told the players before the West Ham game that they would hear him talk down their title chances.
“He told them to pay no attention because his intention was to take the pressure off the team and put others under the microscope.
“He also told the players that he believes they will be champions this season.”