Phil Dowson is ready to speak freely about Henry Pollock. A few months ago, the Northampton Saints director of rugby winced when journalists brought up his teenage tyro. Since then, substance has backed up the swelling hype.

“Henry hadn’t played a Premiership game for a year and there was all this hoo-ha,” says a typically measured Dowson.

“He had massive potential. But had he shown anything? Yeah, in training and for England Under-20. Now we can talk about him… because he’s f------ good.

“At the time, he could have gone into the Premiership and been found out. People would have gone: ‘Flash in the pan. He’s had all this smoke blown up him.’ Now you can blow smoke. He’s played four or five games at this level, been man of the match for England A. Now, I’m comfortable saying he’s a baller.”

This comes with the firm caveat that Pollock, who turns 20 in January, remains extremely green. That said, the back-rower’s transition to the senior ranks has been startlingly assured – even given the promise he has shown in age-grade action.

Returning to Saints after a starring role in a World Championship victory for England U20, which complemented their Six Nations triumph earlier in the season, Dowson held back Pollock for the first two Premiership games of the new campaign.

There was a brief cameo against Harlequins and then, when Sam Graham suffered a devastating knee injury early in the East Midlands derby at Leicester Tigers, a real chance opened up as Pollock came off the bench at the ground where he had made his league debut a year previously.

His lip curls into a grin as he remembers hearing boos as he joined proceedings at Welford Road. Saints lost 24-8, yet Pollock reviewed footage and felt encouraged that he was “there or thereabouts”. Graham, “an amazing bloke”, told him in the changing rooms afterwards that there was an opportunity to seize. And Pollock has done so, forcefully.

Flitting between openside and No 8, Pollock has averaged almost 45 running metres per 80 minutes in the Premiership according to Stats Perform; second only to Tom Willis and Ben Earl among back-rowers. He is clocking up an average of 16.6 tackles each game as well. Sam Dugdale, Lewis Ludlow and Tom Gordon – three renowned workhorses – are the only back-rowers bettering that.

Besides this irrepressible involvement, with turnovers thrown in, Pollock has also maintained a habit of winding-up opponents. He plays with swagger and spikiness. This much seems innate. As one age-group coach recently explained: “People say Henry knows where the camera is… but he was like this in school games with nobody watching.”

Dowson disputes that Pollock is a “cocky” character and insists he is “not a gobs----”. In person, Pollock lives up to that image. He is straight-talking yet open and polite with a self-effacing sense of humour. On the subject of the on-field scraps, such as him whisking the scrum-cap off the head of Australia A flanker Tom Hooper, Pollock is amusing.

“I don’t know,” he says. “I was always competitive as a kid, even in the garden with my mates or my brother and sister. I wanted to be the best at… probably everything. I love the aggressive nature [of rugby] and thrive in it, I think. I’m at my best when I’m confrontational and on the edge.

“There’s a fine line there. I don’t want to be over the top and getting sent off. But you want to be in a state in your mind and body where you’re able to go out there and perform.”

If he has been the target of any sledging by rivals hoping to put him back in his box, Pollock prefers to keep that to himself. He did, however, enjoy his friend Afolabi Fasogbon performing another wave last weekend, this time towards Northampton loosehead Tom West when Gloucester were awarded a scrum penalty.

“I had a good chat with Afo afterwards and there was more to that story than meets the eye,” Pollock adds. “I’m keeping my head down and doing my thing, I guess. But I love Afo, and I think that’s the way it should be; young guys coming through and showing what they’re made of, not being shy of the older guys ahead of them.”

Fasogbon, Pollock and the other U20 world champions have stayed tight. Pollock’s eyes light up at the mention of Asher Opoku-Fordjour’s England debut against Japan. Interestingly, he acknowledges that it was helpful to have Mark Mapletoft and other U20 coaches involved in the England A fixture last month. Pollock certainly seemed at home, producing a relentless display.

A difficult U20 game last season in Scotland, one of just two during the Six Nations in which he did not win the player-of-the-match award, represented an “eye-opener” that reminded him to keep grafting. Pollock had plundered a hat-trick in a win over Italy, yet struggled to click before finding his groove again against Ireland and France.

He will have to deal with surging expectations, yet feels sure that his family can keep him grounded. At the suggestion that his social media feeds could be flooded with highlights of himself, Pollock shrugs. “You can’t shy away from it, I don’t think,” he says. “You go on your phone and it’s there. You kind of watch it and scroll to the next video.” The line between arrogance and confidence is thin, but Pollock, you sense, harbours a healthy level of determination.

“You never want to be that character that thinks they’re better than everyone else and you never want to be the quiet kid,” he says.

“I think you want to be the guy that comes out of nowhere and shows everyone up when people don’t think you can do it. Back when I was younger, I was quite naughty in school and my teachers didn’t really believe in me. I remember sitting down with Mum and she said that if I worked really hard, I could show up those teachers and get A-stars.”

Pollock stops a short moment and smiles before a well-timed dig at his own academic career. “I didn’t do that… but that was the chat!” he laughs. “And it correlates to the same thing here.”

“Dominant collisions” in defence have been a “massive focus” for Pollock of late. He has bulked up to around 105kg (16st 7lb) without compromising on dynamism and aims to be “the most explosive and the most technically advanced” he can be. Among a vast inventory of skills, his passing is highly impressive. Richard Hill is mentoring Pollock and Steve Borthwick has had a quick conversation.

Intriguing decisions for Borthwick and England

Northampton’s matches in the Champions Cup, beginning with Castres at home on Saturday, signify another milestone. Expect Pollock to slip back to openside with Juarno Augustus fit again. And do not expect him to go into his shell.

As a mark of how quickly pecking orders can change and rearrange, Pollock travelled to last season’s absorbing semi-final against Leinster at Croke Park as part of a “non-23 p--- up”. He and other squad members flew out to Dublin at 6am and returned at 5am the following morning. They did not feel the need to book hotels. Through the beer goggles, Pollock felt unashamedly jealous of those out on the field.

Fitness permitting, he will be in the thick of such occasions from here on out. And there will be intriguing decisions for Borthwick and England management when the Six Nations and summer tour roll around.

Does Pollock stay with the U20s, for the Six Nations and then another World Championship? Or, with another England A fixture against Ireland and a senior trip to Argentina and the US coinciding with the British and Irish Lions tour, does he get fast-tracked?

“I don’t know yet,” finishes Pollock, who would relish helping the U20s defend their titles. “We’ll have to wait and see. It’s above my pay-grade, to be honest, what I do.”

We do know that those in the bigger pay brackets are fond of Pollock; and with good reason.