Maguire's mum comes to his defence after 'disgraceful' jibes
The Manchester United centre-back won his 59th cap as a substitute in England's 3-1 friendly win in Glasgow on Tuesday but was jeered by Scotland fans every time he touched the ball.
His evening at Hampden Park was further marred by a second-half own goal that gave the home side hope.
England manager Gareth Southgate, speaking after the match, railed against the "ridiculous treatment" meted out to the defender.
"It's a joke," said Southgate. "I've never known a player treated the way he is -- not by the Scottish fans, by our own commentators, pundits, whatever it is."
Now even his mum, Zoe Maguire-Wilkinson, has defended her under-fire son.
"As a mum, seeing the level of negative and abusive comments which my son is receiving from some fans, pundits and the media is disgraceful and totally unacceptable to any walk of life, never mind someone who works his socks off for club and country," she wrote on Instagram.
"I was there in the stand as usual, it's not acceptable what's been created, over nothing. I understand that in the football world there are ups and downs, positives and negatives but what Harry receives has gone far beyond 'football'.
"Harry has a massive heart and it's a good job he's mentally strong and can handle it as others may not be able too. I wish this sort of abuse on nobody!"
Two years ago, Maguire was an ever-present for United and earned a place in the Euros team of the tournament after helping Southgate's side reach the final.
But a drop in form and few opportunities under manager Erik ten Hag, who recently replaced him as captain at Old Trafford with Bruno Fernandes, has increased the pressure on Maguire.
The 30-year-old defender was upbeat after Tuesday's game, despite his barracking from the Scottish fans.
"It pretty much takes the pressure away from my teammates and puts it all on myself," he said. "It makes them play better, for sure.
"It is a little bit of banter and it is a hostile environment, coming away to Scotland.
"I would not say I am a person who struggles with pressure mentally. I have been through a lot in the last couple of years and I have been Manchester United captain for nearly four years."
Celtic manager Brendan Rodgers, who briefly worked with Maguire at Leicester before he left for Old Trafford in 2019, said the root of the issue was abuse from United fans.
"I find it a real shame," he said. "He's a good guy, he is obviously a top-class player and the focus and noise around him sadly has probably been created by his own club supporters and that has spilled out onto other supporters."