The 27-year-old is set to move to the Toffees after the two sides reached an agreement over an initial £22 million deal that could rise to £24m, and Mourinho has admitted that the France international is on the move.
"No details," Mourinho told Sky Sports after goals from Jaun Mata and Marouane Fellaini gave his side a 2-0 win over Hull City in the first-leg of their EFL Cup semi-final.
"But before the match I was informed by [executive vice-chairman] Mr [Ed] Woodward that the situation is close. So Morgan is more than probably going to Everton."
Schneiderlin has featured just eight times for United this season, but has spent only 11 minutes on the field in the Premier League.
The former Southampton player was more heavily involved last season under Louis van Gaal, though, making 29 appearances in the English top flight.
A £25 million signing from the Saints in 2015, Schneiderlin was the subject of a bid from West Brom this month that was rejected, prompting Everton to push ahead and reach an agreement.
He attended Everton's training ground to undergo tests last Friday and looks set to team up with Ronald Koeman, who coached him at Southampton, once again.
Mourinho had already admitted Schneiderlin and fellow wantaway Memphis Depay would be allowed to leave the club if the right offer is made.
"I will allow them to leave if the right offer comes," Mourinho told a press conference last week. "Until this moment? No.
"Is this a good situation? No. Why not? Because I don’t think about them as options in this moment."
While Scheiderlin's move appears imminent, Memphis' future remains unclear, with the latest reports in France stating Lyon have been told they will have to pay €17m for him.