Billy Vunipola's England snub last autumn seems a long and distant memory after his stunning form for both club and country – and World Cup winner Neil Back believes he’s come of age.

Back joined a panel of judges at Premiership Rugby’s offices to narrow down an all-star shortlist for the Green Flag Forward of the Season award, and they struck a consensus with Vunipola.

And it is easy to forget the hulking No.8 is still only 22, having picked up his first England cap in June 2013.

If not for Ben Morgan’s unfortunate leg break, however, Vunipola could still be on the outside looking in as far as England is concerned after being axed by England head coach Stuart Lancaster in favour of the Gloucester man during the autumn internationals.

Vunipola responded by standing out at the Six Nations earlier this year, yet Back insists his return to England’s starting XV is wholly on merit.

“He’s always been a big unit and very powerful, but he’s developed his offloading to make those yards count and bring other people into the game,” said the former Leicester back-row.

“It’s very easy to just carry the ball and then go in contact, but he’s got the knack of when to offload and get the ball forward.

“He’s been shortlisted for the European player of the year, and you don’t get shortlisted in that if you haven’t had a good season.

“He’s been fantastic for both club and country and very dynamic with Saracens. He belies his age, he’s only 22 but shows a real maturity and understanding of the game.”

Vunipola is part of a shortlist bursting at the seams with back-row talent, joining Northampton’s Samu Manoa, Wasp Nathan Hughes and Exeter Chiefs duo Thomas Waldrom and Dave Ewers – Green Flag's Forward of the Season, and the winner will be revealed at the Aviva Premiership Rugby Awards on 20th May at the Park Lane Hilton, London: Waldrom and Ewers could well be in the mix for the Red Rose come the World Cup in September while Hughes becomes England-qualified in June 2016.

And with Morgan and evergreen Harlequin Nick Easter all jostling for contention at No.8 too, Back insists the competition will only make Vunipola stronger.

“As a coach, particularly Stuart (Lancaster) in the England job, you want competition. Competition means players have to maximise their individual potential to get in and stay in the team,” added Back, who was joined on the judging panel by Jack de Menezes (The Independent), James Hopkins (BT Sport), Emma Thurston (Out On The Full Rugby), Martin Gillingham (ITV) and Neale Harvey (The Rugby Paper).

“I remember myself being challenged by lots of people.

“Many people talk about Dallaglio, Hill, Back, but we had Joe Worsley, Martin Corry and Lewis Moody all who were potentially as good.

“You need that and Nathan Hughes is brilliant news for England should he wish to pledge his allegiance in the future.

“Nathan’s 23, Billy’s 22, Ben Morgan is 26. My head and heart tell me different things about England – my heart’s saying we’ll win the World Cup, my head’s saying we’re not quite there.

“But if you think of their ages at the minute, in two, three or four years’ time they’ll not only be very good but very experienced. So watch out New Zealand and the Lions tour in 2017 and the next World Cup.”

Green Flag – proud partner of Aviva Premiership Rugby – has revealed the shortlist for the Green Flag Forward of the Season award. The winner will be announced on 20th May. Follow us @GreenFlagUK or facebook.com/GreenFlagUK – www.greenflag.com