North star is the guiding light

George North is Wales' big hope as they begin life without Shane Williams with a grudge rematch in Ireland

Giant steps: George North is still only 19 but he has scored nine tries in 16 appearances for Wales and made a big impact at the World Cup in New Zealand (Getty Images)

There is, indubitably, a lot to like and admire about George North. His try-scoring record, his personification of the brashness of youth – already into double figures in caps while still a teenager – and, by all accounts, his splendidly even temperament.

"Some boys come through and get arrogant when they have smoke blown up their arse," said the curly-haired prop Adam Jones, who is to Wales's front row what North is to the back three, which is to say extremely important. "George is a nice kid, very grounded." Pretty much the only thing not going for North is that he is not Shane Williams, but that is a rare instance of something beyond the 19-year-old's control.

"I'm not sure I can do the same job as Shane," said North, when we met in the last few hours before Wales hopped over the Irish Sea for today's match in Dublin. "He was in his own class, unbelievable, and obviously such an influential player.For me and Alex [Cuthbert] we've really got to step up and try and fill that jersey as best we can."

That will not be a problem for the Scarlet, at 6ft 4in and 16st-plus, or Cuthbert, his fellow wing, a Test debutant who is even bigger. The metaphorical gap left by the international retirement of Williams last November is different.

"George is like Shane, only with about six stones and five inches extra," was how Jones put it, and he afforded Williams some high heels in that assessment. While the retiree is enjoying his newfound downtime in Las Vegas, an XXL version of his No 11 jersey will be drawn over North's shoulders, with the 21-year-old Cuthbert on the right and the comparatively long in the tooth Leigh Halfpenny – Cardiff Blues both – at full-back.

"I've been with Shane for the last 10 years in the squad," said Jones of the little man of 58 tries from 87 caps. "There were times when we'd just give the ball to Shane and hope he'd do something. It's someone else's opportunity now. George? He's just a freak, isn't he?"

Another description of this King's Lynn-born, Welsh-raised son of an English RAF officer and a mum from Anglesey, from the former Scotland wing Thom Evans, was "an absolute beast". But the heartening thing for Welsh supporters about North is that in his own, profoundly un-Shane-like way, he is having a similarimpact. Maybe, just maybe, we will say one day that Shane Williams was no George North.

What we do know is that North, since his two tries against South Africa on debut in November 2010, has rattled up nine in 16 appearances and shared in Wales's march to the World Cup semi-finals, defeating Ireland along the way. He is no automotive, tramline runner; rather an exciting jack of all trades, big enough, to run through tackles and bounce off the equally monstrous Alesana Tuilagi in a pool match against Samoa. But he has a sidestep too; a lively, low-slung shift of feet in tight spots that wrong-foots opponents large and small.

True, that he is still learning the game – he has hardly played more matches for the Scarlets than for Wales and has yet to play a minute in Ireland, having visited only on family holidays – means those sidesteps and moments of adventure over security are not always perfectly timed.

Sitting next to him, you cannot help noting the bum-fluff wisp of nascent sideburns on his young face, but you also thrill at the realisation that here is one of the quickest four in the Wales squad (quite possibly the quickest one, but the conditioning coach refuses to let on) who was clocked a year ago running 40 metres in 4.5 seconds. In a huge Welsh backline – only "Pens", as North refers to Halfpenny, is under 6ft – it is essential that at least one of them can shift.

"There's a few lumps going round, yeah," North said. "I think it [the Ireland game] will be great to watch. One of the games you wish you were playing in and watching at the same time. We're going in with a 'w' over Ireland already and they'll want something back as the World Cup was a massive stage. They'll be coming hard and chucking everything at us."

The quarter-final featured North swapping wings with Williams to confound Tommy Bowe – "They didn't put any high balls up so it was good, I guess," said North – and ended with Wales 22-10 winners. They negated the running of the flanker Sean O'Brien. Or "they outfoxed us", as the Irish lock Donncha O'Callaghan wrote in his autobiography. "We respected the improvements they had made, but we looked at the young Welsh players who had made a big impact... and we expected to beat them."

Now the question is what Wales are expecting in the rematch. They are relieved to have Rhys Priestland and Jamie Roberts fit in the midfield, where Ireland have selected Jonny Sexton over Ronan O'Gara (who started the two Wales wins in 2011) at fly-half and are without the injured Brian O'Driscoll and unavailable Keith Earls. Wales's pack lacks Gethin Jenkins, Alun Wyn Jones, Luke Charteris and Dan Lydiate form the World Cup formation plus the hooker Matthew Rees, who wasn't in New Zealand.

North admitted to a few aches and pains, and so appreciated the ice chambers of last week's camp in Poland. But he said: "I'm buzzing now. What do I enjoy most about playing for Wales? It sounds like a cliché but just the rugby, really. At this level everyone can do their job so when you do yours you haven't got to worry about anything else. When that happens it's one of the best feelings in the world."

Ireland: R Kearney (Leinster); T Bowe (Ospreys), F McFadden, G D'Arcy (both Leinster), A Trimble (Ulster), J Sexton (Leinster), C Murray (Munster); C Healy (Leinster), R Best (Ulster), M Ross (Leinster), D O'Callaghan, P O'Connell (capt, both Munster), S Ferris (Ulster), J Heaslip, S O'Brien (both Leinster). Replacements: S Cronin (Leinster), T Court (Ulster), D Ryan, P O'Mahony (both Munster), E Reddan (Leinster), R O'Gara (Munster), D Kearney (Leinster).

Wales: L Halfpenny; A Cuthbert (both Cardiff Blues), J Davies (Scarlets), J Roberts (Blues), G North; R Priestland (both Scarlets), M Phillips (Bayonne); R Gill (Saracens), H Bennett, A Jones (both Ospreys), B Davies (Blues), I Evans, R Jones (both Ospreys), T Faletau (Newport Gwent Dragons), S Warburton (Blues, capt). Replacements: K Owens (Scarlets), P James (Ospreys), A Powell (Sale), J Tipuric (Ospreys), L Williams (Blues), J Hook (Perpignan), S Williams (Scarlets).

Referee: W Barnes (England).

Ireland v Wales is on BBC1 today, kick-off 3pm