Anthony Martial left the Manchester United training ground after 11 minutes on Monday morning due to illness.
Martial, 24, reported at United's Carrington training complex with the rest of his teammates but the MEN understands he was sent home as he is still not fit enough to train.
Martial travelled to Southampton with the rest of the United squad but was taken ill overnight and stayed at the team on hotel on Sunday.
The United executive vice-chairman Ed Woodward was also driven into Carrington in his first sighting at the United training ground. Woodward was in attendance for United's enthralling 3-2 comeback at Southampton on Sunday and Solskjaer gave an injury bulletin ahead of Wednesday night's Champions League visit of Paris Saint-Germain.
"It's a knock just above the knee," Solskjaer said of David de Gea. "So we'll have a scan and check on him tomorrow. Hopefully he can be ready for Wednesday but can't promise anything now. Dean came on, very assured, had a couple of half-saves to make but he was tidy and safe with the ball at his feet.
"Anthony had to stay in the hotel, he got ill overnight and he is down here still. Paul [Pogba] and Scott [McTominay] hopefully can start training with us tomorrow, Luke is out still, we're not 100% sure.
"Jesse [Lingard]'s back. Phil Jones is out [and also ineligible]. David: I don't know how he'll react to his knock and bang. Alex had an issue towards the end but hopefully won't be too bad."
United will qualify for the round-of-16 if they get a point against PSG at Old Trafford.
