Midfielder Tom Cleverley, 25, could be the first with Aston Villa leading the £7million chase, with Everton and Valencia also interested.
If Cleverley leaves on a permanent basis - a loan is also a possibility - the Daily Star Sunday understands he will receive a £1m pay-off from United.
Fellow midfielder Shinji Kagawa could return to Borussia Dortmund for £8m and striker Danny Welbeck is in demand with a host of clubs. There could also be United exit business involving striker Javier Hernandez, midfielders Anderson and Marouane Fellaini and goalkeeper Anders Lindegaard.
Fellaini, though, currently has an ankle problem.
Not all these deals will be completed before the transfer window closes at 11pm tomorrow.
But United's in-and-out transfer negotiations illustrate the extent of the revolution launched by new boss Louis van Gaal.
On the countdown to the closure of the transfer window, Van Gaal said yesterday: "Blind is coming for his medical, so maybe we will have a new player.
"I also believe that by the time we play next Marcos Rojo will have his work permit.
"Departures? It is up to the players involved.
"I always say this because it is their decision.