Manchester United are tracking Celtic teenager Kieran Tierney, as revealed by Sportsmail on Tuesday.
The 19-year-old defender's reputation continues to enhance north of the border, and United's head of scouting Marcel Bout watched Tierney in the Old Firm draw against Rangers earlier this month. A United representative is likely to attend Sunday's Scottish Premiership game at Hearts to scout Tierney again.
But why are United so interested? BRIAN MARJORIBANKS gives the full lowdown on the young Scotland international.

Who is Kieran Tierney?