Exiled from the Manchester United first team and out of the England reckoning, it's remarkable to think that less than three years ago Luke Shaw was almost universally regarded as the country's next great left-back.
When Roy Hodgson picked Shaw in his 23-man England squad for the 2014 World Cup at the expense of Ashley Cole, it felt like a logical changing of the guard. The teenager had established himself as the obvious successor with two impressive Premier League campaigns at Southampton, and appeared destined for a bigger stage.
Chelsea wanted Shaw to inherit Cole's position at club level too, and made Southampton aware of their interest in signing a player who supported them as a boy and was denied a place in their academy at the age of eight amid concerns that he was too small.
But Manchester United desired Shaw too and offered terms -- a transfer fee rising to £30 million and a wage package reportedly worth £100,000-a-week -- that Chelsea, according to then-manager Jose Mourinho, were both unable and unwilling to match.
"If we pay to a 19-year-old boy what we were being asked for, to sign Luke Shaw, we are dead," Mourinho insisted. "We would have killed our stability with financial fair play and killed the stability in our dressing room."
The implication was that Shaw had not achieved enough to earn his lofty status as the world's most expensive teenager and, judging by the events of this season, working with the defender on a daily basis at Carrington has done nothing to change Mourinho's mind.
"He stayed behind in Manchester because I am playing with Daley Blind, Marcos Rojo, Matteo Darmian, and all of them are playing the way I like full-backs to play," Mourinho told a news conference when asked why Shaw had been omitted from his squad ahead of United's 1-0 win over Saint-Etienne in the second leg of their Europa League round of 32 tie. "Luke has to wait for his chance, he has to work better and better, knowing that I give nothing for free."
Shaw has made just seven Premier League appearances this season and while there are examples of players who have rebounded from Mourinho's tough love treatment to make themselves key to his plans, the likelier outcome is that his future lies away from Old Trafford. If that proves the case, Chelsea could do worse than put him back on their wanted list this summer.
Despite no lack of effort or expense, the left side of Chelsea's defence has been plugged rather than properly filled since Cole's departure. Cesar Azpilicueta did a solid job out of position, Filipe Luis and Baba Rahman failed to establish themselves and Ryan Bertrand blossomed only after being sold to Southampton. Marcos Alonso has provided crucial attacking balance since Antonio Conte's switch to a 3-4-3 in September, but significant doubts remain about his defensive capabilities.
Shaw is a more explosive athlete than Alonso, renowned at Southampton for his ability to contribute to attacks with frequent forward surges without often being caught out of position defensively. He was beginning to exhibit the same qualities for United before suffering a horrific double leg break in September 2015.
More than two years on, there is no reason to believe that Shaw is still troubled by any lingering physical effects of that injury, though he has suffered numerous other fitness setbacks since. The concerns about him relate as much to his mind as his body.
Long before Mourinho made his feelings known on Tuesday, the sense among some at United was that Shaw has not shown the drive to get himself in peak shape, improve his game and cement his starting place.
His conditioning has now been criticised by Louis van Gaal and Mourinho and he lives with four old school friends in Manchester, though he insists this is not an issue. "Some people might think we're always partying but it isn't a party house," he told the Guardian back in August. "These are my best friends -- I've known one since we were eight -- and they want the best out of me."
Chelsea would need to do their due diligence on Shaw's attitude as well as his physical state, but the list of talented players -- many of them young -- who have made Mourinho look foolish at other clubs after languishing on his naughty step is now too long for his assessment to be relied upon.
How keen United would be to sell Shaw to Chelsea is another matter, but he loses value every day that he isn't considered for selection. Mourinho clearly has significant doubts about the 21-year-old, and made clear by allowing Juan Mata to move to Old Trafford in January 2014 that he sees no intrinsic problem in giving an expendable player to a rival.
The least Chelsea can do is ask the question because while his career has stalled in recent months, Shaw still has the talent to be the answer for arguably the only questionable area of Conte's team.