The 55-year-old’s search for a left-back this summer – an area in desperate need of reinforcement – has ground to a worrying halt after the club’s pursuit of Alex Sandro from Juventus petered out last month.
And with Mourinho now placing emphasis on signing another central defender, for reasons which remain unclear, it is a real possibility that Manchester United will end the summer without a new left-back.
But according to M.E.N‘s Ciaran Kelly, the Portuguese boss remains keen on securing Tierney from Celtic this summer.
The Scot made his senior debut aged 17 and has since emerged as a regular starter for both Celtic and Scotland, the holy grail of footballing achievement north of the border. His discipline, raw energy and tenacity in defence has attracted Mourinho, whose over-reliance on Ashley Young proved costly last season.
He even travelled up to Glasgow back in May to watch Tierney in action against Costa Rica, only to discover the 21-year-old had been ruled out with a calf strain shortly before the game.
Supporters will be outraged if they club opts against signing a new left-back this summer. Perhaps Tierney – young, sprightly, powerful, fearless – could serve as the long-awaited solution.