The pair have known each other for almost two decades and Stones revealed they often share jokes over texts – meaning the Manchester City defender was in “no doubt” that his England team-mate would find his form at the World Cup.
The two centre-backs may cross the Manchester divide, with Maguire captaining Manchester United, but they are long-time friends and have built a fine understanding at the heart of Gareth Southgate’s defence.
Maguire has been dropped by United recently and was also jeered by a small section of England fans earlier in the year.
But Southgate kept his faith in the 29-year-old and it was repaid with a fine display in the 6-2 win over Iran on Monday before Maguire went off with illness.
“First of all, no doubt at all,” Stones replied when asked if Maguire would settle in with England despite his club form.
“Harry hasn’t played much at his club, but to come in and play like he did – I don’t think anyone saw a bit of rust on him.
“That’s great credit to him and I’m so happy for him and everyone who played. As a player you want and need to be playing and have a good rhythm. But for him to come in to play as he did is credit to him.”
While they may be fierce rivals when City face United, Stones revealed the pair stay in touch when not on international duty.
“We swap texts, yes, but nothing about football. Sometimes that can be the best thing. I am sure you have been in a situation where you have hurt your leg or whatever and everybody is bombarding you with questions about how it is.
“You just don’t want to be asked about it sometimes. We have got a good enough relationship to put things to one side and be normal.
“If I had my phone, I could probably tell you (what the texts said)!
“Just general stuff, or it might be something one of us has seen, or a joke. Probably me making a joke – that’s the first thing that came into my head.
“I think it is special that we have that sort of relationship that, when we are rivals at clubs, football has moved on a lot from 10 or 20 years ago, and that gets put aside very quickly.
“When we are on the pitch playing against each other, it is, ‘I want to beat that person and that team’. But as soon as that final whistle blows, we shake hands, the friendship resumes and we move on.
“It (when he met Maguire) must have been before I was 10. We must have played against each other. I was at Barnsley and he was at Sheffield United.
“You know the good players in the team and you’ve seen the size of him now! He was a big kid.
“The partnership on the pitch comes with time and us having played together for a few years now. Sometimes the environment that we have created here – I can’t put my finger on why it is – it just clicks and it happens and you have a bond.”