Manchester United recruited Sanchez in a swap deal from Arsenal in the January transfer window.
Sanchez scored three goals in 18 games in all competitions in the second half of the 2017-18 Premier League season.
The Chile international still hasn’t scored in the current campaign despite six appearances so far.
Martial and Rashford have fallen down the pecking order following Manchester United’s signing of the South American.
Former Arsenal striker Wright believes Sanchez needs to be dropped in favour of Martial or Rashford.
“He can’t warrant a place when you’ve got Martial and Rashford,” Wright told BBC Radio 5 Live.
“Mourinho has to give them a chance now. He isn’t doing it.”
Manchester United finished in second spot in the Premier League table last term but ended up 19 points adrift of Manchester City.
The Red Devils won the Europa League and the League Cup in their first season under Jose Mourinho’s management.
The 20-time English champions signed Shakhtar Donetsk star Fred, FC Porto defender Diogo Dalot and Stoke goalkeeper Lee Grant.
Manchester United lost 1-0 to Chelsea FC in the FA Cup final at Wembley last term.
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