The Red Devils head to the midlands fresh from sealing their place in the Europa League final on Thursday, when they lost the semi-final second leg 3-2 at Roma but progressed 8-5 on aggregate.
Villarreal await in Poland but the focus now is on Villa as United continue a tough run of four matches in eight days, with home games against Leicester and Liverpool following hot on the heels of Sunday's match.
"Sunday at 2pm is not the problem," Solskjaer said. "That was always scheduled. Tuesday, Thursday after Thursday, Sunday, that's a big problem.
Solskjaer has to strike a "balance of who plays when" in this quickfire Premier League triple-header, which will just come too soon for Anthony Martial.
The 25-year-old has been lied low with a knee injury sustained on international duty with France in March, but the forward is set to play a part before the end of the campaign.
"We've got belief and hope that he'll be available for the last few games of the season," Solskjaer added.
"He's working hard to get fit. He won't make these three games, though. That's unfortunate because we would have needed him."