Manchester United are continuing to closely watch Celtic's Kieran Tierney.

The Daily Mirror is again reporting that Jose Mourinho sees the 19-year-old as his long-term option at left-back.

United were credited with a serious interest in Tierney in January, accompanied by speculation regarding a potential £10million deal, but if Mourinho wants to lure the highly-rated Scotland international to Old Trafford, he will have to go above that price tag.

It is understood that the Portuguese boss and his staff are impressed by Tierney's 'disciplined lifestyle' and 'total dedication to his career', making him the perfect player to replace Luke Shaw.

Arsenal, Chelsea and Manchester City are also keen on Tierney who is expected to be the subject of a summer offer from United.