The Chelsea midfielder is now on the verge of completing his £40m switch to Old Trafford.
An image appeared on social media yesterday which appeared to show the Serbian wearing United training gear.
In a new United top he was seen smiling and showing off a No.31 jersey.
And after it was reported the medical had started yesterday it has now been claimed he has passed.
The Manchester Evening News say it is done and dusted.
Matic could be announced shortly and might face Sampdoria in Dublin on Wednesday.
United boss Jose Mourinho revealed that the 28-year-old was desperate to come to Old Trafford last night.
He said: "I'm waiting for news.
"I know that he wants that very, very much and when a player wants very, very much the chance is bigger.
"So I think we have a chance but in football until it's official, I have seen so many things happen that I refuse to say more than I am telling you now.
"I don't know [about the picture] because I was not there.
"Number 31 is a free number.
"It was [Bastian] Schweinsteiger.
"It's a free jersey, we have a few free and 31 is one of them."
