Nick Cain talks to Saracens coach Phil Morrow about the amazing Billy Vunipola

Billy Vunipola is a tank, and at Twickenham two weeks ago London Irish found him virtually unstoppable. The pulverising charges of the gargantuan Saracens back row carrier, which scattered or mangled the Irish defensive line, prompted two thoughts after the double-header.
The first was that Sarries' gain has been immense whereas Wasps offensive capabilities have been halved judging by their display against Harlequins. The second was that Twickenham will soon become Big Billy's second home, whether it's for England – for whom he made his test debut in Argentina in June – or Saracens, as they hunt the game's major trophies.
The younger of the two Vunipola brothers is 20, and although Mako, a year and 10 months his elder, was making the bigger waves during the summer as a Lions test loosehead during the series victory Down Under, Billy is hot on his heels.
His decision to leave Wasps this summer and join Mako at Saracens was followed by selection for England's trip to South America. Having scored a hat-trick of tries in a devastating six minute spell against a CONSUR side in the first game in Uruguay, he won his first cap off the bench – and scored a debut try – in the 32-3 first Test win over Argentina, and also came on as a replacement in the second Test win in Buenos Aires to clinch the series.
For the last decade England have been deficient in forwards who cannot just break the gain-line, but smash it to smithereens, and the 6ft 2in Billy – or Viliame, as he was christened by his Tongan parents – has shown already that he has the physicality to revolutionise England's attack.
A trimmed down Billy, chosen initially at blindside by Saracens after mainly wearing the No.8 jersey at Wasps, has started this season at a fighting weight of 130kg (20st 4lb). To achieve that he lost 5kg (11lb) during five weeks of pre-season training. That still makes him 15kg (2st 3lb) heavier than powerhouse England No.8s like the incumbent, Ben Morgan, and his predecessor, Nick Easter. It also means he tips the scales a few kilos heavier than most of the props in the Premiership, including his brother.

Phil Morrow, the Saracens performance director, says that Vunipola's explosive power and size makes him ‘The Phenom' of the Premiership. Morrow, who was with Ulster and Ireland before joining Sarries, starts off being measured about the club's new acquisition, but he cannot suppress his enthusiasm as he talks about the hard work and discipline that saw the big man shed kilos of ‘fat mass' in pre-season to become leaner, meaner, and more mobile.
“Sometimes in rugby you get a heavy guy and sometimes an explosive guy, but they don't often come together. When you get a mix of the two you've got a player with massive potential, and Billy is that bit heavier and more powerful than even those guys. 120kg is very big for a backrow player, so if you have someone 10kg heavier it can be a huge advantage.”
He adds: “Being a Pacific Islander helps – there are not too many English people like that. Stephen Ferris was like a white Islander in terms of natural power when I was with Ireland, but Billy is at a completely different level in the force he can produce and how quickly.
“His ability to move, how dynamic he is, and how much force he produces, it is way beyond anything I've ever seen, and I'm coming into my 14th season of pro rugby. If we can make him reproduce that more and more, his potential is phenomenal.”
Morrow explains that to make the gains, Vunipola has had to deal with pushing his pain threshold. “Being fit as a pro rugby player is about what you can do when you're tired, because if you are trying your hardest you are going to be tired. Billy's ability to work harder and push himself through the (pain) barrier has been pleasing. Mako would say Billy's got it quicker than he did – it probably took a year for Mako to realise it – but because he's already been in a pro environment.”
He continues: “Our aim is for Billy to average at 85 per cent to 100 per cent of his maximum heart-rate for 45 minutes of any given match, and sometimes for 55 minutes or more. If I asked you to do that you would feel you were going to die, but you're not going to. Instead, it's about teaching your body that you can still function at that level.”
When I spoke to the brothers at the Saracens training ground this week ahead of today's home clash against a vaunted Gloucester back row, including Matt Kvesic, Akapusi Qera, Sione Kalamafoni and Morgan off the bench, Billy acknowledged he has his work cut out.
However, he was also candid about his ambition, and about being envious of his brother's achievements. By the end of the chat it's clear that he does not intend to blend into the background as support cast with the 2015 World Cup only two years away, while Mako – with nine England caps and three Lions caps already – becomes a headline act.
Billy says watching his brother on the Lions tour wasn't easy. “It was a funny one. Obviously, I was really proud of him to make the Lions in the first place. But, at the same time, I would have liked to be in the same position. Being in Australia, and having the whole atmosphere around the Lions, and not being in the whole rugby circle was, not disappointing, but I felt like…”

“Jealous,” offers Mako.
Billy continues: “Yeah, envious. It would have been good to be in with him and seeing him and Toby (Faletau) getting on so well. I didn't really watch it. That's how much I didn't like it. I watched the Barbarians game, but then I only caught replays. Probably the next one I watched live was the last game.”
However, for all the sibling rivalry the bond between them, forged during their boyhood together in Pontypool, and Marlow – when their father Fe'ao took up coaching after playing 32 Tests at hooker for Tonga – remains strong.
So, Billy says, does their father's influence. “My Dad was pretty tough on us. We love carrying the ball, having the chance to run over people, and basically be the centre of attention…we never want to be second best.”
Mako takes up the story: “He never wanted to see us take a backward step. If we had a chance to physically dominate he wanted us to take it whether we had the ball, or in defence. He was hard on us in that way – he always felt we had to prove we were more physical than our opponents. It's just the culture and mentality of the Tongans and other Islanders.”
Mako says of his brother joining him at Saracens, and living in the same house, “It's good to have him around and he's settled in pretty quick. We share with Eoin Sheriff and one of our cousins. I've got the best room, obviously, being senior!”
They are also on the same page when it comes to putting in the hard graft. Billy says he has made spectacular gains by doing extra training, and points out that his body shape now is a far cry from the barrel-shaped behemoth who took the field as an 18-year-old for Wasps weighing 152kg (almost 24 stone).
It was clear then that, although his low centre of gravity, wide girth and power made him hard to stop, his mobility and work-rate were significantly reduced. Now he accepts that rigorous conditioning is the key to reaching his goals.
“It's something I will always have to do. My first day of pre-season I thought it would be easy, but we were straight in at the deep end with fitness. It's been tough but I've enjoyed it.”
Billy elaborates: “We have a Wattbike and loud music. It's always on the same level, and can read if you're going slower or faster. They have heart rate monitors on you so they can see how hard you're working. As you go quicker, it gets harder or stays the same, it doesn't ever ease off. If you're on a spin bike and you start kicking faster, it gets easier. The Wattbike doesn't. We stay on from 20 minutes to half an hour – and that's after training or a weights session. After a weights session we also do a ‘Prowler' (a weights sled) which takes a lot out of your legs – and then we do a Wattbike.”
Billy says that Saracens training is more cutting edge than at Wasps.
“The sessions here are probably a bit tougher. Shorter but much more intense. It's just a little bit more professional. I'm not trying to knock Wasps, but training is videoed and you analyse every little thing you do. I wouldn't say more demanding, just more clinical. At Wasps they were a bit broader, kind of old school, just go out and smash people.”
He says he has felt the benefits already. “It helps me get more involved in the game, rather than just ghosting around… that is the biggest thing for me and my brother, just trying to stay in the game and not being a passenger.”
Billy says that he does not care if Saracens pick him at blindside or No.8 as long as he's playing, and he is not getting ahead of himself either for his new club or England, acknowledging that he has to establish himself in both teams first in the face of fierce back row competition.
With Saracens losing in the semi-finals of the Heineken Cup and the Premiership last season – coming second to a monster Toulon pack – Mako says that Billy brings the firepower they were missing.
“We wouldn't have signed him if he didn't bring anything different. We now have a few more weapons in attack and I am looking forward to seeing how it works. Being brothers we know what each other do and you read off his body language. We have not really had much chance yet to play together but hopefully this weekend we will get another.”
The last time the Vunipolas joined forces before the 42-20 trouncing of London Irish was for England U18 against Fiji and Japan when Billy was a mere 16. He has come of age since then, and Gloucester had better be ready to deal with a force of nature unrivalled in the English league.