Mata was expected to leave Manchester United in the summer when Mourinho took charge after the Old Trafford boss sold him at Chelsea.
Mourinho returned to Chelsea in the summer of 2013 but Mata failed to impress the Portuguese and was sold to United seven months later for £37.1million.
The Red Devils boss fuelled rumours of a rift between the pair when he took Mata off in the 2-1 Community Shield win over Leicester having brought him on just 12 minutes before.
Mourinho has since admitted he has no issues with the Spaniard, claiming it was not his decision to offload him to United.
And Mata has now reiterated his manager's comments and has laughed off talk he was going to leave Old Trafford in the summer.
"My relationship with Mourinho has never been bad," Mata said. "Many lies were told about me and Mourinho when he arrived at the club this summer.
"It bothered me that every day I had to read and listen to rumours that weren't true. With him I'm fine.
"You read a lot of comments on Facebook and twitter but they just make you laugh."
The 28-year-old playmaker has been crucial for Mourinho at United this season, scoring two goals and providing one assist so far.