An on-loan goalkeeper is not always a signing to set pulses racing and Sam Johnstone remembers how, on arriving at a downbeat Villa Park in January 2017, it took a little time for his merits to be appreciated. “You’ve come in, it was difficult, you did hear some of your own fans saying: ‘Go back to Manchester United,’” he says. “It was just a difficult period, probably that month and a little bit of February. Then it kicked on.”

These days Johnstone’s position as No 1 at Aston Villa is unimpeachable. A persuasive case can be made that he is the best keeper in the Championship and, at 25, he feels he has found a home after 10 temporary spells at seven different clubs. After those uncertain beginnings, when a Villa side still adjusting to life in the second tier lost seven games out of eight, there has been no looking back and it was no surprise when Steve Bruce asked José Mourinho if he could take Johnstone for a full season last summer. Mourinho obliged and Johnstone, whose team look play-off bound but could apply late pressure on the automatic promotion places with a home win over second‑placed Cardiff City , is now in popular demand for a permanent stay.

“I enjoy seeing fans say that because I enjoy being here,” he says. “Basically I’ve gone from one end of the spectrum to the other. That’s something I’m proud of, to have turned their opinions of me, and I think the goalkeeping coach [Gary Walsh] has probably seen a change in me. You just need those games to get your confidence.”

It has been a breakthrough period for a player who started out playing Sunday league football in Lancashire with the appropriately named Euxton Villa, whose alumni include David Unsworth and Andy Lonergan. Johnstone was scouted at the age of 10 by Colin Fairhurst, who had launched his father Glenn’s career more than a decade previously. Glenn played a handful of games in goal for Preston North End under John Beck before a knee injury cut his professional career short; it was to United that Fairhurst took the younger Johnstone, though, and it is a strange thought that, barring a dramatic development of events, he will eventually depart without making a competitive appearance in a decade and a half.

“If you leave, then the one downside is that you haven’t done that despite being there since you were 10,” he says. “I’d have liked to have done it. But you’ve got the world’s best goalkeeper, David de Gea, at the club and you can’t wait around forever. You realise you might have to take the example of someone like Michael Keane, who went to Burnley and has gone from strength to strength [with Everton and England].”

Johnstone, Keane, Jesse Lingard and – later – Paul Pogba were among a close-knit youth team vintage at United that have almost all made a living from the game. Keane departed permanently in 2015 and now has four England caps; that is firmly in Johnstone’s thinking too and he gives the impression that, after so many staccato stints up and down the divisions with Oldham, Scunthorpe, Walsall, Yeovil, Preston and Doncaster before arriving at Villa, he is in a hurry to establish himself at the top.

“When we were younger Michael wasn’t really in the frame, he was probably a late developer but then he kicked on and progressed quickly,” he says.

“He’s always been a very good player but he went on loan, got games, then decided to leave and carry on that progression. If you choose to leave, you have to choose the right club, the one where you’ll play the most games. Ultimately that’s what whoever picks the England team looks at.

“I have to create my own career. You want to be challenging to get into the England setup. Nick Pope gets into the Burnley team because of an injury, does very well and then gets his call-up. It just shows the manager [Gareth Southgate] is watching and hopefully he has me in mind even though I’m in the Championship.”

Angus Gunn, who is on loan at Norwich City from Manchester City, received a call-up for the Brazil friendly last November so the recent precedent is there. Gunn has long been part of the Under-21 setup and Johnstone believes that may have made him an easier option. He has his own proponents, though. Jack Butland – with whom he featured in England’s victorious Uefa Under-17 Championship campaign in 2010 – recently called him a “Premier League keeper” and suggested he is “firmly in the mix” for a jersey that has no stand-out holder.

“They’ll all be thinking it’s for anyone to take it now,” he says of Butland and his current competitors. “It’s open, and hasn’t been this open for years. Joe Hart’s kept his place over the years and done well but it’s up for grabs in the future. All I can do is keep trying to play well, keep the stats good and hopefully next year we’ll see if I can be in contention.”

Johnstone kept more clean sheets than any other Championship goalkeeper in 2017 and, this season, sits third in the rankings behind John Ruddy and Scott Carson. Premier League clubs were linked in January but all parties would clearly settle for a long-term commitment to Villa should Bruce lead them up. He is keen to stress his contract at United runs until 2019 and there would be no complaints about honouring it.

Aston Villa goalkeeper Sam Johnstone punches the ball away during their goalless draw against local rivals Birmingham City at St Andrew’s in October 2017. Photograph: Barrington Coombs/PA

Patience has become a virtue: after helping Preston, his hometown club, win promotion from League One in 2015 he had hoped to push on but Louis van Gaal would not let him out again and, save for a brief return to Deepdale, he barely played for a year and a half. Learning from De Gea and Victor Valdes in training every day at United sweetened the pill considerably but it “felt like I’d kind of slowed down again, that things kind of came to a stop”.

Grinding to a halt again would, at this point, seem unthinkable. Johnstone – whose younger brother Max has recently been released by United after a couple of years – has now played 145 first-team games, a run that started in 2011 during a spell at Scunthorpe that “made me grow up”. If it is a comment on the way big clubs go about their business that all of those have occurred on loan, then he has, on the other hand, been nourished by his different environments.

“It’s been a bit of a rollercoaster,” he says. “It’s been fun getting games in and getting different experiences but I’m 25 now and ready to settle. Hopefully Villa get promoted and we’ll take things from there.”