Costa, who scored 20 times for the Premier League Champions last term, has struggled for goals this campaign, scoring four in 19 games in all competitions for the club.
He recently apologised for throwing a training bib in the direction of his manager after being left on the bench as an unused substitute against Tottenham Hotspur on Nov. 29.
Speaking to a Spanish radio station last week, Costa left the door open on a possible return to his former club Atletico Madrid, but Mourinho moved to quash speculation that the 27-year-old was set for a premature exit from Stamford Bridge.
“He is happy here, he likes to be here,” the Portuguese told reporters ahead of Monday's Premier League clash against third-placed Leicester City.
“He has I think three more years on his contract. I see him staying at Chelsea for three more years, no problem.
“He said that in football, you never know.
“Atletico is a great club, Madrid is a great city, La Liga is a very good league so why should a player who is 27 years old not think that in football it is possible to be back?
“I don't see that as a problem.”
Chelsea, who are 16th in the table and a point above the relegation zone, will be looking to make amends for their shock 1-0 home defeat by Bournemouth on Dec. 5 when they line up against Leicester at the King Power Stadium. – Reuters
Original source: Costa will see out contract - Mourinho