Ajax awaits in the final, and so does the final verdict on the Red Devils' season. The Portuguese boss is aware and he will not take any unnecessary risks in a fixture that will be a mere formality to close the season in the Premier League.
De Gea could have played his last game at Old Trafford, as it looks like Mourinho will opt for third-choice goalkeeper Joel Pereira, as well as a host of virtually unknown names for the Old Trafford crowd.
The Londoners will arrive wanting to put a miserable season behind them, even though Allardyce's men finally managed to avoid relegation. Manchester United have their mind on the Europa League, and Palace on their holidays.
Possible lineups:
Manchester United: Pereira; Bailly, Jones, Smalling, Mitchell; Pogba, Tuanzebe; Mata, Rooney, Martial; McTominay.
Crystal Palace: Hennessey; Ward, Kelly, Tomkins, Schlupp; McArthur, Milivojevic; Zaha, Puncheon, Townsend; Benteke.