English publication 'The Daily Mail' reports that the Chilean will be benched against Spurs, with Marcus Rashford set to start in his place.
Rashford was in fine form in midweek as United saw off Bournemouth and it appears that he has played himself into Mourinho's team for Saturday.
Whilst originally intended as a way of giving his stars a rest, the seven changes made by Mourinho against the 'Cherries' also gave fringe players a chance to stake their claim, something that Rashford did and then some.
Sanchez was one of those who was dropped to the bench against Bournemouth and it appears that he will suffer the same fate at Wembley.
The former Arsenal man has failed to live up to his billing since his January move, scoring just twice in nine league starts, with his status as a guaranteed starter also affecting Rashford and Anthony Martial's game time.