ESPN is reporting that the Red Devils are keen on a move to bring the 20-year-old to Old Trafford this summer as Jose Mourinho looks to bolster his defensive options.
The same report says that Mourinho has made signing a new left-back his priority this summer and that Tierney is now his top target in that position.
According to the same story, Manchester United have been keen on signing Danny Rose from Tottenham Hotspur in the past, but they view Tierney as more of a long-term option.
The defender has been a regular fixture in the Celtic team this season and has scored three goals in 28 SPL games for the Scottish side.
Manchester United are bound to be linked with a host of players in the coming weeks and months as Mourinho looks to assemble a squad capable of winning the Premier League next season.
The Red Devils currently find themselves in second place in the table as they look to try and finish as runners-up to Manchester City.
Manchester United could still win a trophy this season – and they take on Tottenham Hotspur in the FA Cup semi-finals next weekend.
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