The 22-year-old was angered by Mourinhos decision to substitute him at half-time during Uniteds win over Brighton before the international break.
Shaw reportedly asked Mourinho: Why are you always picking on me?, which then sparked an argument inside Uniteds dressing room.
After the match, Mourinho publicly criticised Shaws performance against Brighton, claiming that the player lacked aggression and was defensively suspect.
Ashley Young has been Mourinhos first-choice left-back for the majority of the campaign but the 32-year-old is a doubt for the match against Swansea after suffering a knee injury during Englands draw with Italy on Tuesday.
Mourinho, however, says he would have no hesitation in selecting Shaw against Swansea.
He is available hes always an option, said Mourinho.
Young was available to play against Brighton and I started with Luke Shaw, so thats not a problem.
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