Slimline Billy Vunipola at last comes out of his brother’s shadow

Billy Vunipola’s greatest fear on a rugby field is that he might be caught “ghosting around, being a passenger”. A combination of watching what he eats, punishing workouts and a switch of club to Saracens has made him leaner, meaner and the most exciting young prospect in England’s pack. The only ghost in this story is the trail of opponents going bump in the night as Vunipola sweeps them out of his way.

Take the television commentary for the 20-year-old’s second cap – like the first, it was as a replacement for England’s incumbent No 8, Ben Morgan, on tour in Argentina in June. “Oh, oh, oh Billy,” chuckled Eddie Butler and Andy Gomarsall, as various Pumas were wiped out from the sides of rucks. The use of just the Christian name for the Tonga -descended prodigy was apt for two reasons: Billy is instantly recognisable with his long-bodied, short-legged frame of 130kg (yes, that is leaner – read on for the detail); and there was already another Vunipola, his elder brother Mako, doing good things for Saracens, England and the Lions.

So Billy it is, for the ease of reference, and to be face to face with him before today’s match with Gloucester – where he may butt heads with his positional rival Morgan among 16 England players on view – is to appreciate his transformation from the pear-shaped teenager who weighed 152kg when playing for Wasps at Twickenham in April 2011. Billy has now shed more than 20kg and Phil Morrow, Saracens’ performance director, said: “Billy’s raw potential is massive, way beyond anything I’ve seen before.”

Considering Morrow was previously head of fitness for Ulster and Ireland, working with Steve Ferris, Sean O’Brien, David Wallace and Jamie Heaslip, this is an eyebrow-raising statement.

“Being a Pacific Islander definitely helps,” said Morrow. “There are not too many English people like that. Billy is at a completely different level in terms of how much force he can produce and how quickly he can do that. Sometimes in rugby you get a heavy guy and sometimes an explosive guy, when you get a mix of both, there’s the excitement. A back-rower is normally 120kg. Billy’s got 10kg more than that.”

Billy will be Saracens’ blindside flanker today, as he was in the win over London Irish last week, but when asked about England he said: “I don’t really have a preference. I have to establish myself in the team first before I have an inkling of where they want me to play.”

He also commented that with Tom Croft and Tom Wood around, the No 6 prospects were slim, but that was before the news of Croft’s season-ending knee injury.

In any event, covering two positions could make Vunipola Jnr a great bench man at least for the November internationals against Australia, Argentina and New Zealand.

Despite the stories that the brothers’ dad Fe’ao, a former hooker for Tonga, Pontypool, Pontypridd and Caerphilly, would have preferred them to play for Wales, both parents brought Billy to Loughborough to train with England Under-18s. “He was still young enough to play Under-16s but he was already colossal then, a big lump of a guy who was shy and didn’t say a lot,” recalled the England Under-18 head coach John Fletcher. “I could never claim it was the greatest piece of talent spotting, everyone knew about him and he went on to Harrow School while his brother was at Millfield.”

Billy’s first England U18 appearance was against South West Academies at Bath, almost exactly four years ago. “Straight from the kick-off he tackled a guy and ripped the ball off him,” said Fletcher. “He has an unbelievable skill set. He’s most comfortable and happy in conditioned games, touch games – breaking down defences. But Saracens have got a range of coaches and they will give him good skill development.”

Since arriving at Saracens six weeks ago Billy has shed four kilos, and Morrow reckons another couple of kilos dropped over the next year will be sufficient. How have they done it? “Eating regularly, and eating the right things,” said Billy, who is sharing a house with Mako, one of their cousins and the Saracens flanker Eoin Sheriff.

And then there are the terrors of the “prowler” – a kind of one-man scrum machine – and the “watt bike” which unlike a normal spinner, doesn’t get easier when you pedal harder. “In a match we expect to see Billy at 85 per cent up to 100 per cent of his maximum heart rate for 45 minutes,” said Morrow. “A normal person at 90 per cent of their maximum heart rate will want it to stop. Being a rugby player is not about not getting tired – it’s about what you can do when you are tired.”

Billy is teetotal, whereas Mako likes the occasional beer. While Mako toured with the Lions, playing in all three Tests, Billy scored a hat-trick of tries in England’s non-cap match against a South America XV in Montevideo and another one in the first of two wins over Argentina. He was proud but also envious of his brother. Of Morgan, he said: “We got on quite well. I fed off his experience of international rugby. He gave me a few pointers on the back of the scrum, and the cadence.”

When Fe’ao played for Tonga against England in the 1999 World Cup the headlines concentrated on the Islanders’ awful disciplinary record. Mako has not forgotten watching at Twickenham as Fe’ao and friends were hammered 101-10. Otherwise the likes of Jonah Lomu and the former Wallaby back-rower Willie Ofahengaue have given Tonga-descended players a fine name, and that is the dynasty England are investing in with the Vunipolas.

Billy Vunipola was mostly a No 8 for Wasps and played there with England in the summer but Saracens have deployed him as a blindside flanker. Vunipola’s ability to tackle hard, clear out at rucks, maul powerfully and offload with quality make him viable in both positions, although in the line-out, at 130kg, he is more likely to lift than jump. Tom Croft was England’s blindside for last season’s Six Nations Championship but is now injured. Ben Morgan of Gloucester is England’s man in possession at No 8, while Tom Wood of Northampton and Harlequins’ Chris Robshaw have excellent claims to be a starting No.6. Joe Launchbury and Courtney Lawes are second-rows who can play blindside, while the second-tier Saxons squad includes a bunch of back-rowers – full caps James Haskell, Tom Johnson and Thomas Waldrom among them – who have been leap-frogged by Vunipola.