Manchester United are set to run the rule over Celtic's Kieran Tierney again at Sunday's Old Firm derby as Jose Mourinho formalises his summer transfer plans.
Sportsmail understands that Mourinho's trip to Hampden Park last month, when he watched Scotland's 1-0 defeat by Costa Rica, had initially been scheduled as a scouting mission.
Tierney had been recommended by United scouts and Mourinho was hoping to check on the left back, until the 20-year-old withdrew from the squad.
One thing that stands out straight away with Kieran Tierney is his personality.