Sanchez is expected to soon complete a switch to Old Trafford with talks progressing on a deal that will see Henrikh Mkhitaryan join Arsenal.
And he had been tipped to make his first appearance in a United shirt when Jose Mourinho’s men visit Burnley tomorrow afternoon.
Sanchez needed to have signed for the Red Devils and be registered with the Premier League by 12pm today to line up against Sean Dyche’s men.
However, that deadline has now passed and Jose Mourinho will have to wait before he can call upon his prospective new signing.
The failure to seal Sanchez’s switch means Mkhitaryan, in turn, will not make his Arsenal debut against Crystal Palace tomorrow.
Sanchez is likely to don the red of United for the first time when they travel to Yeovil in the FA Cup next Friday.
Mkhitaryan’s will have to wait a little longer to feature for Arsenal as he is cup tied in the Carabao Cup so will miss next Wednesday’s showdown with Chelsea too.
The trip to Swansea on January 30 is likely to mark the start of the Armenian’s career with the Gunners.
United, meanwhile, will be looking to tighten their grip on second place when they take on Burnley at Turf Moor.
Arsenal need to beat Palace at the Emirates in order to stay in touch with the Premier League’s top four.