Manchester United are looking to sign a left-back before Tuesday’s transfer deadline, but one thing must happen in order for them to do so.

The Red Devils are short in that position, with Luke Shaw their only recognised senior option on the left side of defence.

Patrick Dorgu has been sounded out as a deputy, but the Dane has not featured in that role all season having been shifted further forward by manager Michael Carrick since he took over the reins at Old Trafford.

The Daily Mail claimed that United had a backup plan in case they did not land a left-back before the end of the transfer window, which included trialling Lisandro Martinez or new midfielder Carlos Baleba as makeshift deputies, or utilising Noussair Mazraoui and Diogo Dalot’s versatility to use them as cover for Shaw.

The other option would be Harry Amass, the academy graduate, staying put, despite him not being part of the first-team picture amid talks with Burnley over a potential move.

Now, Sky Sports reports that there is a key step that must be taken for Carrick to get his left-back addition this summer.

That is for Joshua Zirkzee to leave the club - either on loan or permanently - before Tuesday’s deadline.

The Dutch striker has found himself on the periphery at Old Trafford, behind the likes of Benjamin Sesko, Matheus Cunha and Bryan Mbeumo in the pecking order as the sole centre-forward in Carrick’s 4-2-3-1 shape.

As such, he has been the subject of interest from Juventus and Fiorentina, who were both looking to bring the former Bologna man back to Serie A.

Juve advanced in talks over taking him on loan, before turning their attentions to Newcastle’s Nick Woltemade, who has flown into Turin to undergo a medical.

Fiorentina were also credited with an interest before they agreed a deal with Everton to sign Beto, with the Toffees looking to replace him with former Arsenal forward Folarin Balogun from Monaco.

If Zirkzee were to leave United before the window shut, it would open up some space in the club’s wage structure for a left-back addition to be made.

That, however, could prove difficult if another suitor does not cement their interest quickly.

United have been linked with the likes of Newcastle’s Lewis Hall, Barcelona’s Alejandro Balde and Ian Maatsen of Aston Villa in their hunt for a left-sided full-back.