Manchester United boss Jose Mourinho is reportedly considering an approach for Celtic full-back Kieran Tierney.
The 20-year-old, who came through the youth system at Celtic, has scored three times in 75 first-team appearances for the Scottish giants since making his debut during the 2014-15 season.
According to The Mirror, Mourinho is closely monitoring developments surrounding the Scottish defender, and the Red Devils head coach could launch a £15m move ahead of the 2017-18 campaign.
Man United have already added Victor Lindelof to their defence this summer, but questions remain over the left-back position, with Luke Shaw struggling to impress last season and uncertainty surrounding the future of Italian international Matteo Darmian.
Tierney, who still has four years remaining on his contract with the Hoops, has also previously been linked with Arsenal.