Manchester United are weighing up a move for Celtic fullback Kieran Tierney.

The Mirror says United boss Jose Mourinho has been watching developments closely on 20-year-old Tierney and wants to make a £15m move.

Scotland international Tierney is highly regarded and United have been sending scouts to check on his progress and the reports were glowing after his performance against England this month.

Mourinho wants a new left back with Luke Shaw's future at Old Trafford uncertain and the United left back is aware that the club are looking at different targets.

Arsenal have also been looking at Tierney but the left back has four years left on his current deal and Celtic want him to stay for at least one more year.