England manager Gareth Southgate lambasted spectators at Wembley who booed defender Harry Maguire during a 3-0 win against Ivory Coast in a friendly on Tuesday.
Sections of the crowd booed the Manchester United defender as he made his first international appearance of the year following a similar reaction when his name was read out as a substitute for the game against Switzerland.
Maguire has received criticism for his performances for his Premier League club Manchester United which has spilled over into the national team as well.
There were boos when his name was announced at Wembley Stadium before the kickoff against Ivory Coast and when he made his first touches. However, Southgate insisted the defender would be key to England's World Cup campaign later this year.
"I don't understand how it benefits anybody because we are either all in it together or we're not," Southgate said.
"I would imagine if you asked a few actually why were they doing that, they might not even be able to answer that because it becomes a mob mentality."
He warned that the hounding of Maguire could make other players fear that they might be next, stating former England players John Barnes and Ashley Cole faced similar treatment, as did Raheem Sterling.
"We're not going to win a World Cup with a load of players that have got three or four caps. That's not happened in the history of the game," he said.
"He's [Maguire] top quality and in my opinion he's the best centre back at his club as well," Southgate said. "It's ludicrous. It's almost like every time he steps on a football pitch every action is analysed to death."
England midfielder Jordan Henderson said he could not understand why sections of the home support had booed Maguire.
"I can't get my head around what happened at Wembley tonight," Henderson, who was an unused substitute, tweeted. "Harry Maguire has been a colossus for England."
Maguire helped England reach the 2018 World Cup semi-finals and the European Championship final last year.
"Without him, the progress made at the last two tournaments would not have been possible," Henderson added. "To be booed at his home stadium, for no reason? What have we become? What happened tonight was just wrong."
The jeering of Maguire overshadowed a routine win for England, with 10 changes from the side that beat Switzerland 2-1 on Saturday.
First-half strikes from Ollie Watkins and captain Raheem Sterling either side of a red card for Ivory Coast skipper Serge Aurier put the home team in total control.
Southgate made multiple changes in the second half as he looked at some of his fringe players ahead of Friday's World Cup draw before Tyrone Mings headed home from a corner in stoppage time.