Sanchez is likely to start for Manchester United in their FA Cup fifth round clash against Chelsea at Stamford Bridge on Monday (7.30pm).
Injuries to Anthony Martial and Jesse Lingard mean the Chilean is set to keep up his record of starting in every round of the competition so far this term.
Sanchez, though, has failed to live up to expectations since his mid-season move from Arsenal in January 2018.
He has only scored two goals all campaign in a United shirt and has started just one Premier League match since November, though he did score against his former side in the 3-1 fourth-round win at the Emirates in January.
Parlour believes the visit to Chelsea could be the moment Sanchez rediscovers his form from his Arsenal days.
And the pundit reckons a goal at Stamford Bridge would go a long way to doing that.
“Manchester United have got a couple of injuries, Lingard’s out, Martial’s out,” Parlour said on talkSPORT.
“But, as Ole Gunnar Solskjaer said, maybe this is the night for Alexis Sanchez.
“He’s not really clicked in a Manchester United shirt, but if you can get the best out of him and he can suddenly get the form back he had at Arsenal, you’ve certainly got a magnificent player on your hands.
“It’s all about confidence, and his was shot a little bit under Jose Mourinho.
“He didn’t play on a regular basis, he was in and out of the side where he was used to playing week in week out.
“When your confidence does get hit, whether the tactics didn’t fit into the way he wanted to play.
“But Ole Gunnar Solskjaer will be the man to know if he is getting back into form, in training as well.
“If you start getting in the right areas in training, it will all click sooner or later, because he is a quality player.
“When I saw him at Arsenal he was magnificent to watch.
“At times he gave the ball away too much but he always was a player that made things happen and scored brilliant and vital goals.
“Once they get that back, that goal goal could kick-start his Manchester United career again.”