The Reds' capture from Sporting Lisbon will kick off his United career with a start at Old Trafford in the Premier League.
The 25-year-old goes straight into Solskjaer's midfield as the Reds look to end on a high before the winter break.
Fernandes is one of four changes from the United XI that started against Manchester City in the 1-0 Carabao Cup semi-final second leg victory at the Etihad.
The Portuguese newcomer comes into the engine room with Nemanja Matic suspended following his red card against the Blues.
While Fernandes makes his debut, David De Gea, who was superb against City on Wednesday, celebrates his 300th Premier League appearance for United.