The forward was an unused substitute in his side’s 0-0 draw with London rivals Tottenham Hotspur on Sunday, and was visibly upset having not been given any gametime – returning from a warm-up during the game, he pulled off his bib and threw it in the direction of the Portuguese manager.
Yet after the game, the ‘Special One’ downplayed any talk of a rift between himself and the former Atletico Madrid frontman.
"If he wants to hurt me, it's not with a bib,” Mourinho said. “I have a good relationship with him, no problems."
Mourinho felt that the 27-year-old was privileged to be sitting on the bench, yet refused to divulge into any more talk about the Spaniard when asked by the BBC.
"If he [Costa] watched the game with some attention from the bench he will know what is needed from him,” he said.
"I think Diego is privileged because he is last one on the bench. Everyone else has been on bench.
"Costa didn't play. It's not right to talk about someone who didn't play.”
Despite the draw, which leaves the Blues in 14th place in the EPL standings, Mourinho felt this was his side’s best display all season as they look to continue their climb up the English standings.
"I am more than happy with the performance,” he said.
"I am happy with the team collectively. It was the best Chelsea performance of the season, against a dangerous team. My players did everything to try and interpret my defensive ideas the with ball.
"We had control of the game and had the best chances. My team deserved more than a point."
Chelsea will back themselves to grab maximum points as they faced bottom-placed Bournemouth in their next fixture on Saturday.
--------------------------------------------------------------------------