The defender has struggled for game time under the Portuguese and was hauled off at half-time of the Red Devils' FA Cup quarter-final win over Brighton & Hove Albion on Saturday.
According to Kaveh Solhekol at Sky Sports, Mourinho's treatment has come in for strong criticism:
Kaveh Solhekol @SkyKaveh
Source close to Luke Shaw: "Mourinho's treatment of Luke is an absolute disgrace. If he has a problem with him the decent thing to do would be to keep it in-house. If this kind of abuse happened in any other workplace there'd be a case for constructive dismissal. It's disgusting"
Shaw has been rarely used in the Premier League this season but has started all four of Manchester United's FA Cup games. However, Mourinho opted to replace him with Ashley Young after just 45 minutes and explained why after the game, as shown by Samuel Luckhurst at the Manchester Evening News:
The Red Devils went on to win the tie 2-0 but Mourinho's decision to take Shaw off has sparked much debate. United were not at their best during the game but Shaw was far from their worst performer and had done little to warrant being replaced, per ESPN FC's Scott Patterson:
Former Manchester United midfielder Paul Scholes said that he now expects Shaw to leave the club in the summer, per Indy Football:
Indy Football @IndyFootball
Paul Scholes on Luke Shaw: "I think he could be brilliant but his manager will still find something wrong with him. It is disappointing because when Luke Shaw came you thought what a player that is and he could be the best. It's a relationship that, come the summer, will end." https://t.co/Nlka9LLTXS
The defender joined Manchester United from Southampton in 2014 and was widely tipped to develop into one of the best full-backs in Europe at Old Trafford. However, after a bright start to life at the club, he suffered an awful double leg break in the UEFA Champions League against PSV Eindhoven in September 2015 that sidelined him for a lengthy spell.
Shaw has struggled to rediscover his top form side that injury and has failed to become a regular at the club, despite their lack of options at left-back. The defender has come in for frequent criticism from Mourinho who also said in January that "I don't see many left-backs better than this Luke Shaw," per Rob Dawson at ESPN FC.
Alex Shaw at ESPN FC offered a neat observation of Mourinho's treatment of Shaw:
Shaw is said to be unhappy with Mourinho's recent behaviour, but he has not yet made a decision on his future and could see out his current deal which runs until summer 2019, per Jamie Jackson at The Guardian.
The defender's Manchester United team-mates are understood to be shocked and angry at Mourinho's treatment of the Englishman, per John Percy and Ian Whittell at The Telegraph.
There's little doubt that Shaw has the quality to succeed at Old Trafford and Mourinho's continued criticism of the 22-year-old is somewhat confusing. Sports writer Jonathan Shrager said there might be other factors at play:
Jonathan Shrager @JonathanShrager
Me personally, I’m a tad confused by the whole Shaw situation. We’ve been receiving mixed messages about Luke all season from the manager. Certain things lead me to suspect that there’s something additional going on behind the scenes, about which we aren’t being told #MUFC
Shaw's future at Manchester United certainly appears in real doubt, and unless he can convince Mourinho of his qualities the club may well decide to sell him in the summer, rather than risk him running down his contract.