Sir Alex Ferguson has been left fuming after Phil Jones was selected for Stuart Pearce's England under-21 squad, according to the Daily Mail.
The 20-year-old defender was left out of Roy Hodgson's England squad to face Brazil for the prestige Wembley friendly next week, but got the nod from Pearce to play for the under-21s.
Jones has not started any of United's last four games, and Ferguson is thought to be furious that the former-Blackburn star will have to turn out for the under-21s at Walsall on Tuesday night.
Ferguson said: "I haven't paid much attention to it but I'm surprised he's in the under-21s and not the full squad.
"It's happened quite a few times to players and it's understandable but for the players that's more difficult to manage because once a player gets into a full squad he thinks he's achieved what he wants to achieve.
"Taking the step back can be hard to manage but he's 20 and maybe he's as good as the under-21 squad are going to get."
Jones will get a first opportunity to play alongside new club-mate Wilfried Zaha, as the Crystal Palace winger also makes Pearce's under-21 squad.
The tricky wide-man agreed to join United in a deal thought to be worth up to £15m during the January transfer window, but will not join up with his new Old Trafford teammates until the end of the season.
Jones has five caps for his country, and was part of Hodgson's England squad for last summer's European Championships.
And Jones is not the only player set to step down from full national team to under-21s - Jonjo Shelvey, Raheem Sterling and Jordan Henderson have also been selected by Pearce.
The England under-21 manager wants to take as strong a squad as possible to this summer's under-21 European Championships, and is thought to view this friendly as an ideal opportunity to bring his best young players together for some vital training.
Hodgson is also keen for the youngsters to get crucial tournament experience next summer, and agreed not to select the players for next week's friendly with Brazil on the grounds that they form part of Pearce's plans for the UEFA tournament in June.
But Ferguson is thought to be furious that Jones stands to play in the summer tournament - risking possible burnout after a long club season.