Mata signed from rivals Chelsea on 25 January 2014 for what was then a club record fee until United splashed out £59.7m for Angel Di Maria in the summer.
Despite going missing at times in games and being brought off due to struggling to make an impact in certain matches, the 26-year-old scored six goals in his first half season at the club and has added another five to that tally this season.
Carrick hailed Mata’s influence at United on and off the pitch, both as a footballer and a person.
“He’s just a little magician, isn’t he? So clever and with so much ability – he’s a pleasure to watch,” Carrick told MUTV.
“Playing against him over the years, I knew how good he was and we see it in training every day; some of the things he does really stand out.
“That left foot of his can open up any defence and, despite having such a slight physique, he’s a terrific player.”
In addition to his impressive performances on the pitch, the diminutive forward has become a popular figure in and around the club since making the journey up north, and has even found himself handed an unusual position inside the dressing room.
“I have to say he’s such a nice lad. He speaks English very well and is very intelligent,” Carrick added.
“He’s even had a little job of translating [for the Spanish contingent] this year!”
It hasn’t been all plain-sailing for Mata at United this season. The QPR game last weekend wasn’t the first time he has been sacrificed in order for more cutting edge in attack and there were rumours Mata would leave the club when van Gaal arrived in the summer.
However, Mata’s performances were as good as anybody over the Christmas period and his popularity among supporters is growing all the time, both for his performances off the pitch and endearing personality off it.