United host Swansea after leaders Manchester City visit Newcastle this weekend, so if Roberto Mancini's men slip up at St James' Park the Red Devils will be fully aware of what they have to do to capitalise.
Currently trailing City by eight in the goal difference column, the Premier League is still in United's hands, although they will need big wins over Swansea and Sunderland to turn things around over the final two weeks of the campaign.
Ferguson would have liked to have had Evans among his back four for those games, particularly after his replacement Chris Smalling was at fault for City's winner at Eastlands on Monday.
However, Evans continues to nurse an injury picked up during a recent training session in Cardiff, while Welbeck is still suffering the effects of a clash with Nigel de Jong during the game at the Etihad Stadium. Sir Alex Ferguson hopes the striker will be back for the final day trip to Sunderland.
"Jonny Evans is still injured. He's improving a little bit but I don't think he'll be ready for Sunday," Ferguson said. "Danny Welbeck is still out - he got damaged on Monday night - although I'm hopeful he'll be available for the Sunderland game."
Addressing the challenge of Swansea, Ferguson insisted Sunday's encounter will be no walkover for his side, regardless of the fact Mancini labelled United's remaining fixtures "easy games".
"The way Swansea have played this season has been admirable," Ferguson said on Thursday. "I went to see them last weekend. They want to play football. The manager has stuck by his principles and they've had a fantastic season.
"[Losing at City on] Monday night was a blow to us. We can only do what we can now and hopefully win our game on Sunday. Before we start the game we'll know exactly what we've got to do, because the City v Newcastle game is earlier, so the only advantage we've got is that they go first."