Southampton, beaten 3-2 by United in the League Cup final at Wembley in February, have now won just one of their last eight home games in all competitions while United stretched their winless league run to five.
He again fielded an under-strength XI in Wednesday's 0-0 draw at Southampton, omitting Marcus Rashford, Michael Carrick, Ander Herrera, Paul Pogba and David de Gea, as goalkeeper Sergio Romero's performance earned them a draw.
Jose Mourinho has insisted that Manchester United will do everything they can to keep David De Gea at the club beyond the summer transfer window. "I think the first match against (American MLS side) LA Galaxy in preseason", he said.
Mourinho insists the fact United will finish sixth regardless of the outcome of Sunday's visit of Crystal Palace and that their visitors are also safe from relegation, with three teams already down, means they should instead be playing on Saturday.
"I hope to play Sergio in the final and hopefully we don't have problems with the keepers".
"But David is top in the world and obviously we want to keep the top in the world".
And Mourinho admits he feels fortunate to have such quality options at his disposal.
Oil prices rise in expectation of Aramco supply cut to Asia
Brent crude was up 57 cents, hovering at $50.79 per barrel, while US West Texas Intermediate jumped 61 cents to $47.94. Saudi Energy Minister Khalid al-Falih said on Monday the OPEC-led production cut could be extended beyond 2017.
And the Portuguese, speaking after the game, noted that the Belgian had nothing more than a "little bad feeling" when he came off, before adding that nobody else suffered a knock.
"We have these two guys. So in relation to that, we are in safe gloves".
"We played a good team, a team who tried to win and tried to finish well".
And Mourinho said that, despite an imperfect display, he was pleased with his side's desire to prove themselves ahead of the Ajax clash - signalling out Romero for individual praise.
"I hope the fans on Sunday support the team, they forgive some naivety, they forgive some lack of confidence and I hope Big Sam (Allardyce, Palace's manager) shows he's a good friend and he goes slow".
He said: "We perhaps need to work a little more on the training sessions because the penalties have been very important".