The 29-year-old recently passed 200 appearances for the club and has had plenty of ups and downs since he arrived from Wigan Athletic in 2009.
Valencia experienced two superb seasons early on in his career but was one of many who struggled for form under David Moyes last season.
Speaking to Inside United, Carrick had nothing but good things to say about his team-mate, particularly the way he helps out the defence with his pace.
“Antonio is a pure athlete,” said the midfielder.
“He is immense. It is the work he does that doesn’t get noticed, things like carrying the ball up the pitch for 30 or 40 yards when you have been defending.
“He takes you up the pitch and defenders just back up because they know about his pace. If he can go down the line, then he is pretty hard to catch. He is a great team player and, when you are playing with him, you certainly appreciate that he is on your team.”
Louis van Gaal has used both Carrick and Valencia in defence this season, both performing admirably during the club’s six-game winning run.
Despite being a relatively shy person off he pitch, Carrick believes there is a very determined side to the winger.
“He is pretty much the full package,” added Carrick. “He is reserved but determined at the same time. He is quiet, he is pleasant and he is polite. He is not somebody who shouts and screams in the changing room but I certainly wouldn’t want to get on the wrong side of him.
“He is stubborn and determined. He has got a real desire to win, like everyone at this club.”