Manchester United's left-back position has been plagued by misfortune in recent years.

Since arriving from Southampton in 2014 under Louis van Gaal, Luke Shaw has established himself as the club's first-choice left-back whenever fit. However, persistent injury setbacks have prevented the England international from building sustained momentum throughout his Old Trafford career.

The most significant setback came in 2015 when Shaw suffered a horrific double leg fracture, breaking both his tibia and fibula during a Champions League clash. The injury sidelined him for 64 matches and threatened to derail what had promised to be a hugely successful career.

In an effort to provide greater depth and competition, former manager Erik ten Hag signed Tyrell Malacia. But the Dutchman has endured injury problems of his own since arriving in Manchester, limiting his opportunities and preventing him from becoming a reliable long-term option on the left flank.

This season, however, Shaw has finally enjoyed a sustained run of fitness. With United playing just once a week, the 31-year-old has started every available Premier League fixture, becoming only the fifth outfield player in the club's history to reach that impressive milestone.

With Shaw now entering the final year of his contract, Manchester United are expected to assess their options at left-back this summer. 

After Patrick Dorgu's emergence as a potential left-wing option next season rather than left-back, and Harry Amass' unfortunate injury in the second half of last season, it was expected that United would enter the market for a new left-sided defender, as seen by the links to Newcastle's Lewis Hall.

However, after seeing Noussair Mazraoui's performances at left-back for Morocco at the World Cup, Michael Carrick may be rethinking his transfer priorities this summer.

With Achraf Hakimi firmly established as the national team's starting right-back, Mazraoui has featured as a defensive left-back, forming a back three that has allowed the PSG star to join the attack.

Playing out of position, the 28-year-old is yet to have a bad game out of his natural position on the right, despite facing the likes of Brazil and the Netherlands.

Much like many modern-day managers, Carrick will likely deploy a Manchester United side in a 3-2-5 formation when in possession, with one full-back tucking inside to form a back three, much like Morocco does.

Unlike the other two left-backs at the club, Luke Shaw and Harry Amass, who are both overlapping full-backs, Mazraoui offers Carrick a major tactical advantage if the manager shows faith in the Moroccan full-back.

With Mazraoui playing, Carrick has the major tactical advantage of being able to alternate between making his left-back or right-back more attacking and taking advantage of any potential opposition weakness.

With the 28-year-old excelling so far at the World Cup, it has certainly given Carrick plenty to think about as the club weighs up whether they should target full-back reinforcements over the summer.