Manchester United will be closely monitoring Kobbie Mainoo's first England senior call-up after their latest teenager's involvement caused friction with the Football Association. In 2020, Mason Greenwood's breakthrough caused more harm than good and stalled his international progression.

Greenwood, 22, was named in his first England senior squad for UEFA Nations League fixtures in September of that year.

He earned his first Three Lions cap in a 1-0 win away at Iceland, coming on as a 78th-minute substitute.

However, Greenwood and Phil Foden were sent home for breaking COVID-19 quarantine guidelines in Iceland by leaving the squad's part of their hotel, reportedly meeting two women in another part of the hotel.

After the international break, United manager Ole Gunnar Solskjaer slammed the FA's decision to put Greenwood in front of the media during a press conference with Southgate.

And the Norwegian admitted that he attempted to delay the then-18-year-old's call-up to protect him, having only recently burst onto the first-team scene at Old Trafford.

"It's in their right to call him up. Then again, OK, you call him up; you don't have to put him in front of the world cameras," Solskjaer bemoaned.

The FA was reportedly bemused by Solskjaer's rant because the governing body discusses player fitness and welfare with all clubs.

There was also said to be a belief that United were made aware of the plans to have Greenwood sit alongside Southgate before the media and didn't complain.

Like Solskjaer and Greenwood, Erik ten Hag has overseen Mainoo's incredible breakthrough into the United first team this season.

The 18-year-old midfielder made his debut under Ten Hag last term but has since established himself as a key player, starting the last 12 Premier League games.

He had initially been announced as part of the England U21s squad for the first time, previously earning six caps for the U19s.