Speaking on his Sky Sports podcast, Gary Neville said: "Manchester United have just got to try get to the end of the season and win the FA Cup which is not going to be easy.
"They have to win [this weekend] as the season will be over if they don't. Erik ten Hag has got to look at this season whereby he could finish his first two seasons with two trophies in the bank, one in each season.
"That should never be sniffed at. There's nothing left to say about some of the league performances we're seeing and some of the things we're watching, we've said it so many times before.
"But what we can say is that Ten Hag's future is largely dependent on the FA Cup, as their performances in the league are gone. They are not going to change, now what we are seeing is how they will finish the season."
Man United played out a disappointing 2–2 draw away at Bournemouth last week, putting an end to their 2024/25 Champions League hopes.
The Red Devils will battle Coventry City at Wembley on Sunday for a place in the FA Cup final where they could face either Manchester City or Chelsea.