The club have confirmed the youngster has been managing issues during the domestic campaign and view their player withdrawing from selection as beneficial to his long-term fitness.
A statement read: “Manchester United striker Mason Greenwood has withdrawn from the provisional England Euro 2020 squad, in order to recover fully from an underlying injury that also kept him out of the Under-21 European Championship in March.
“Mason’s club appearances were managed carefully to maintain his availability through the intensive 2020/21 Premier League and Europa League schedules.
“But a further spell of tournament football would not be beneficial and Mason will remain at Manchester United to recuperate and prepare for pre-season training.”
If Greenwood was on Southgate’s list, his withdrawal could free up a place for Arsenal’s Bukayo Saka, Aston Villa’a Ollie Watkins or even a midfielder in West Ham’s Jesse Lingard or Southampton’s James Ward-Prowse.