The Frenchman is set to arrive at the club from Valenciennes this summer.
Manchester United have already been busy making moves this summer. The club tied down the much coveted signature of Dutch talent Memphis Depay earlier this month.
Now they are set to be on the verge of another top talent signing.
It was reported that the club had already agreed personal terms with the 16-year-old, but had so far struggled to finalise a fee with the club. Now it is believed United will pay around €450,000 for his services.
The central-defender is certainly a player who looks beyond his age - tall and imposing at the back with a clearly promising future ahead of him.
Upamecano was recently a part of the French Under-17 side that won the 2015 UEFA European Under-17 Championships in Bulgaria, so he seems to be a real top talent for the future.
Manchester United will now be hoping that Upamecano can make it into the first-team at the club and fulfill his potential at Old Trafford.