Maguire hurt his ankle in the 3-1 win at Aston Villa on May 9 and missed his side's final four Premier League matches of the season.
The England international has had to use a protective boot during his recovery but has not been definitively ruled out of Wednesday's match with Villarreal in Gdansk.
However, Solskjaer admits it is unlikely Maguire will be able to come through a full training session in Poland in just 48 hours' time.
"I will wait for Wednesday," the United manager said after Sunday's 2-1 win at Wolves. "Maybe see if he can run on Tuesday but it is still a bit away. I don't expect him to be ready."