Chelsea have publicly denied offering either player in part-exchange for Manchester United's Wayne Rooney, their No 1 transfer target.
And on arrival in Malaysia for the latest leg of the club's pre-season tour, Mourinho could not have been clearer that both Luiz and Mata are part of his plans for the new season.
Asked about the possibility of selling either, he said: "No chance. No chance."
Mourinho, as expected, stonewalled direct questions about Rooney 24 hours after openly admitting the England striker was his sole remaining target.
United continue to insist they will not sell, while Rooney has made it clear he is not prepared to accept second billing at Old Trafford after nine years of service.
And there was a suggestion Mourinho had Rooney's comments in mind when he was asked in Kuala Lumpur whether next summer's World Cup will provide added motivation for players this season.
He said: "Any player that wants to go to the World Cup, if they are a second choice in their club they are in trouble. They are in trouble."
Rooney, meanwhile, was at United's training complex on Thursday for ongoing treatment on his hamstring injury.