Josh McEachran is still only a teenager but he already knows that appearances can be deceptive and public images distorted. It is something that upsets him, particularly when a reporter inquires whether Ashley Cole has ever aimed an air gun at his kneecaps.

"I don't understand why everyone slags off Ashley Cole all the time because I know that he's actually a really nice and very caring person," says the 19-year-old central midfielder Middlesbrough have borrowed from Stamford Bridge for the season. "All Chelsea's English players are really helpful; John Terry and Frank Lampard have been great but Ashley Cole is probably the one who has given me the most encouragement.

"When I got into the first team he made me feel welcome. He just put his arm around me really, he was always inviting me to things. And, no, to answer your question, he's never shot me."

We are sitting in a quiet corner of Middlesbrough's training ground, around 260 miles north of Chelsea's weekday HQ in Cobham where England's left-back infamously, if accidentally, shot a student on work experience with an air rifle, leaving his victim slightly wounded. Other factors help explain why Cole has turned into the media's pantomime villain, but judging by his charming, poised yet slightly shy demeanour there is little danger of a similar fate befalling McEachran. "Josh has a lovely temperament and personality," says Tony Mowbray, the man entrusted with the task of nurturing a fledgling English talented likened to a young Andrea Pirlo. "And he has so much ability."

By the time Middlesbrough's manager returns the left-footer, who was playing Champions League football for Chelsea at the age of 17, to Stamford Bridge this summer, Mowbray hopes McEachran will have helped Boro, currently fourth in the Championship, back into the Premier League. "It's all good here," says McEachran as he prepares to face Watford, who are managed by one of his heroes, Gianfranco Zola, at the Riverside on Saturday. "This loan has definitely been the biggest step forward in my career. I've been involved in almost every league game and, hopefully, we'll win promotion. I love playing for Tony, I like his whole philosophy, the way he just wants to get the ball down and play. I've fitted in very easily."

Which makes a pleasant change from last season. After being fast tracked by his great mentor Carlo Ancelotti, McEachran's career had seemed to stall suddenly with a loan at Swansea under Brendan Rodgers – a fellow paid-up subscriber to the Barcelona school of football – ending in unexpected disappointment. "It was one of those things in life which just didn't work out," he says. Pressed on what he learned in south Wales, the reply is: "Nothing." A question about his opinion of the current Liverpool manager provokes an uncharacteristically coy "I'll pass on that".

McEachran is much happier enthusing about his new habitat. "Tony Mowbray's brilliant," he says, brightening visibly. "He's always talking to me one on one and giving me lots of information about how I'm doing, which is really helpful. He's taught me a lot already.

"The Championship is a lot more physical than the Premier League and, although I still have to get into the opposing penalty area and create chances, I've had to improve the defensive side of my game, especially as I'm usually playing as one of two central midfielders in a 4-4-2 formation. But the training here isvery similar to what we did at Chelsea. It's all about working with the ball and keeping possession."

McEachran has been reassured to discover that Mowbray is a far from a prophet in the Championship wilderness. "A few teams in this division play really good passing football," he says. "I've been very impressed with Derby and Blackpool. I like Brighton and Watford, too, but you'd expect that sort of style when they're managed by two former Chelsea players in [Gus] Poyet and Zola."

He is enjoying English football's second tier so much that when, last week, Rafael Benítez gave serious, unforeseen contemplation to the idea of recalling him to Chelsea for the second half of the season, McEachran pleaded to be allowed to continue his development on Teesside. He is now "99.9 % certain" not to be summoned back south this month.

If his knack of intercepting rather than tackling before using an amalgam of fast brain, subtle movement, velvet touch and wonderfully varied passing range to initiate attacks, have enhanced Boro's football, the club's facilities are similarly superior. Built in acres of undulating parkland a few miles south of Darlington and sitting alongside a swish hotel, spa and golf course – recently ranked second only to the Dorchester as a luxury UK destination by Tripadvisor users – the Rockliffe Hall training complex is among Europe's best.

"Everything's top-class here, it's so enjoyable," says McEachran. "Middlesbrough is really a Premier League club just waiting to get back up there and although Tony didn't have much money to spend last summer what he's done with the bit he had has been unbelievable."

Oxfordshire born and bred, McEachran lives in an apartment within Rockliffe's grounds, which is proving highly convenient for the spa and its assorted therapy pools. "Oh yes, I'm in there quite a lot, i. It's very nice," he says. "And my girlfriend likes coming up here." McEachran's long-standing romance with Brooke Vincent, Coronation Street's Sophie Webster, has left him comfortable in the celebrity limelight, but he has not found the north-east quite the boring, freezing, backwater he perhaps envisaged.

On a winter's day when, admittedly, dark clouds fill the County Durham sky and it feels "a good few degrees" chillier than not just London but Manchester (where he regularly visits Vincent), McEachran is gently teased after electing to pose for the Guardian photographer indoors, but generally this "soft southerner" has adapted well. "It's been nicer than I expected, better than I thought it would be," he says. "In my experience the further north you go the more polite people are. Up here they're really polite, they all stop and talk to you all the time and ask how you're getting on. London's non-stop, 100mph, but people are a lot more relaxed up here."

Most places would appear serene next to Stamford Bridge. "You can't keep on top of everything that's happening down there, can you? Blink and you miss a drama," says McEachran, smiling. "But I've been part of the Chelsea system since I was seven so I've got used to it." The worst upheaval came when Ancelotti was sacked. "I went into the first team under Carlo and he was huge for me," he says. "He's the one who gave me all my chances. I was gutted when he left."

André Villas-Boas, Ancelotti's successor, was equally mesmerised by McEachran's knack of manipulating a football, but noting that, stripped down, the still skinny teenager looked nothing like a professional athlete he commented that all the boy's pace and power was contained in his brain. Villas-Boas meant it as a compliment but the Portuguese also believed the prodigy needed to toughen up on loan and dispatched him to Swansea. "I got on with AVB," says McEachran. "AVB was a great coach and a great manager and I'm not surprised to see him doing very well at Tottenham."

Now Roberto Di Matteo, who placed him in Mowbray's care, has been replaced by Benítez. "I think Rafa Benítez can definitely win round the fans and do well at Chelsea," says McEachran. "If anyone can get Fernando Torres, who is still a great player, back to his very best it's him."

He gives the gossip suggesting Torres is not overly popular in west London short shrift. "I like Fernando. He's a really nice guy, he's quiet and keeps himself to himself; he's down to earth, really humble," McEachran says. "The Spain players all tend to be like that. It's one of the reasons why Andrés Iniesta is my role model."

So would he forsake Chelsea to play alongside Iniesta in Barça's midfield? "Yes, probably," he says. "But not for a few years. First, I want to win promotion with Middlesbrough and then establish myself in Chelsea's first team."