The Red Devils get their season underway against Crystal Palace at home on Saturday.
United have been training as a team this week, and Greenwood is also involved.
But he recently got sent home from England duty for breaching COVID-19 rules, and was given a stern talking to by Ole Gunnar Solskjaer.
And The Sun claims that it is unclear if the 18-year-old will be involved against Palace.
Solskjaer was not impressed with Greenwood's behaviour, and told him that he expects better from the teenager.
Whether Greenwood plays will depend on how much he can impress his boss in training before the game.