Manchester United manager Jose Mourinho has reportedly made Celtic left-back Kieran Tierney his top transfer target in the remaining days of the window.
The 20-year-old has been linked with a string of clubs following his fine form for the Scottish champions last term and has already accrued four caps for the Scotland senior team.
According to ex-Hoops striker John Hartson, Tierney is now being heavily pursued by United in what is left of the transfer window, despite Celtic manager Brendan Rodgers's insistence that he is not for sale.
Mourinho has made three key additions this summer - bringing in Romelu Lukaku, Nemanja Matic and Victor Lindelof - but still has problems in the left-back role, with Luke Shaw considered unreliable due to his ongoing injury woes.
Tierney, who has also been linked with Arsenal in the past, has been with Celtic since the age of seven and has four years remaining on his current deal.