Portuguese boss Villas-Boas has been tipped as a potential successor to compatriot Mourinho at the Bernabeu at the end of the season, with the Real manager's future still the subject of speculation.
Mata worked under Villas-Boas during his ill-fated stint at Stamford Bridge last season, which lasted just nine months before his sacking.
But the 35-year-old has impressed at Spurs this term and Mata feels his old boss has the calibre to coach anywhere in the world.
He told Movistar: "He's able to train any team.
"He's a great coach; modern and young but with experience and qualifications, although his time at Chelsea did not go well at all."
Meanwhile, former Valencia playmaker Mata was reluctant to discuss the possibility of Mourinho returning to Chelsea, where he previously spent a successful three-year spell.
The Portuguese boss is being touted as a potential successor to interim manager Rafael Benitez in the summer.
Mata added: "They (Chelsea) keep fond memories of Mourinho. They did very well, won titles and the fans will keep a great memory.
"But today Mourinho is the coach of Real Madrid and Benitez of Chelsea. We have to be focused on that."