While Antonio Valencia is comfortably first choice on the right of Manchester United’s rearguard, the left-back slot is not nailed down by anybody. In fact, the club have never replaced Patrice Evra since he left for Juventus all the way back in July 2014.
Evra was one of the best left-backs in world football both defensively and going forward during his spell at Old Trafford, where he won five Premier League titles, the 2008 Champions League and three League Cups.
The promising Luke Shaw was signed from Southampton for £30 million and was viewed as the long-term replacement, however it has not quite worked out that way.
Injury issues, including a horrific leg break against PSV Eindhoven, has well and truly stalled his progress. Shaw still continues to have fitness problems and his attitude has been questioned at times.
The former Saints player has firmly fell out of favour with Jose Mourinho and his days at the club appear to now be numbered.
Shaw could link up with Mauricio Pochettino once again with rumours circulating that a swap deal with Danny Rose could be on the cards.
Although, judging by Pochettino’s comments about Shaw in his new book, that could be unlikely to say the least.
“I felt his head was not in the right place to make the sacrifices and decisions that are necessary at that age,” Pochettino said.
The position has been traded between Matteo Darmian, Daley Blind and Ashley Young. While these three players are able to do a job there, none are of the requisite standard to be long-term left-backs with United.
Darmian is more of a right-back, Blind is a jack of all trades but a master at none and Young made his name as a left winger.
There might be another promising British left-back that United could take a punt on, however. That is 20-year-old Kieran Tierney who is earning rave reviews at Celtic and is apparently being courted by United, if reports in The Mirror are to be believed.
The Scotland international has made the left-back position his own at Parkhead and he is tipped for a bright future.
He signed a new six-year contract recently and is a boyhood Celtic supporter so it would be a challenging deal to complete. Arsenal and Tottenham are among others who have also been heavily linked.
Tierney, who made his Celtic debut at just 17 years old and has made eight senior appearances for Scotland, has impressed at the highest level in the Champions League.
He delivered another stellar performance when up against Arjen Robben in Celtic’s narrow 2-1 defeat to Bayern Munich on Tuesday night. Brendan Rodgers was full of praise for his young star after the game.
“I’ve worked with who I consider to be the two best full-backs in Britain – Danny Rose at Watford and Ryan Bertrand at Chelsea. And Kieran is right up there with those boys,” he told BBC Sport.
Shaw is probably just as talented as Tierney but crucially the Scot has so far displayed a superior mentality, which is often the difference between players of that age achieving their potential or not.
Danny Rose is a good player but Tierney could be the perfect long-term solution and replacement for Patrice Evra that United thought they were getting in Luke Shaw.
It might be worth testing Celtic’s resolve.