Chelsea manager Jose Mourinho has brushed off rumours of a potential Diego Costa exit.

The out-of-sorts striker told Spanish radio station Onda Cero that "life is full of surprises" and "you never know" when asked about a potential return to former club Atletico Madrid.

Mourinho said his words had been taken out of context and insisted the striker was committed to the reigning Premier League champions.

"He never said he'd like to go back, he said that in football you never know," Mourinho said.

"Atletico is a great club, Madrid is a great city, La Liga is a great league, so why shouldn't a player, 27 years old, think that in football it is possible to go back?

"I don't see that as a problem. Diego is happy here, he likes to be here. He has more than three years on his contract.

"I see him staying at Chelsea for three more years, no problem."

Costa, who signed for Chelsea for £32million in 2014, has struggled to hit the heights of his first season at the club, scoring just four goals in 17 appearances across all competitions, after netting 21 goals in 37 games last season.

Mourinho's struggling side travel to high-flying Leicester City on Monday, with the hosts – under the guidance of ex-Chelsea boss Claudio Ranieri – moving top with a win.

Mourinho, who replaced Ranieri in his first stint at Chelsea in 2004, said the Italian had plenty to be happy about heading into the clash.

"Why be unhappy, top of the league at Leicester? It's difficult for me to smile, not for him," Mourinho said.