The Scottish left-back has been linked with a move to Old Trafford all season and it appears the Red Devils are closely monitoring his progress ahead of a potential approach in the summer.
Brendan Rodgers’ men face Rangers in the Scottish Cup semi-final this weekend which could be a chance for the youngster to put himself in the shop window.
Tierney has risen through the youth ranks to the Celtic first-team, making 124 appearances in all competitions, scoring and creating 36 goals.
He’s already won two Scottish Premiership titles, two Scottish League Cups and one Scottish Cup since become a regular in the starting lineup.
The 20-year-old is regarded as one of the best young left-backs in Europe and looks to have a bright future ahead of him.
United want him as a long-term replacement for Ashley Young, as the 32-year-old winger has been playing left-back due to the poor form of Luke Shaw – both of whom are out of contract next year.
If Tierney impresses against Rangers, offers could soon come flooding in.