The Austrian international, who joined on loan from German side Bayern Munich on transfer deadline day, will wear the no.15 shirt for Erik ten Hag's side.
You can watch Sabitzer's first interview as a United player from 15:00 GMT today (Thursday) via the United App and ManUtd.com, so make sure you return for that.
Marcel was among the spectators at Old Trafford last night, as United booked our place in this season's Carabao Cup final, following a 5-0 aggregate win over fellow Premier League side Nottingham Forest.
It remains to be seen just when the 28-year-old will make his Reds debut, with his work visa following the temporary switch still yet to be finalised.