Gareth Thomas believes a fast start is vital for Wales in their quest to claim an odds-defying victory over Guinness Six Nations title favourites Ireland on Saturday.

Wales have been largely written off, heading to Dublin after suffering nine defeats in their last  10 Six Nations games to face an Ireland side chasing successive Grand Slams.

Andy Farrell’s team have won 38 of their last 40 Tests at home, being beaten only by England in 2019 and France two years later during that time.

They are also closing in on a Six Nations record-equalling 11 successive wins, remaining undefeated since France toppled them two years ago.

And Wales must halt a poor recent Dublin record, having not landed a Six Nations win there there for 12 years when Leigh Halfpenny’s late penalty secured a 23-21 triumph.

“It is obviously going to be a challenge for us,” Wales prop Thomas said.

“But talking to the boys in the week and last week and saying how exciting it is if we get it right in terms of what we need to do, it will be a class challenge for us.

“It is going to hurt, but it is going to feel good if we get those bits right.

“I think starting fast, just going at them, not accepting their style of play, because if they get what they want they will be very good.

“I think just going after them, going at them, beating them physically, if we don’t start like that then we have no chance.

“They are playing some really good rugby at the minute, but watching the first two games (against France and Italy), people are letting them play like that.

“So it is up to us to go at them defensively and stop that smooth kind of attack they have got.”

Much has been made of a new-look Wales Six Nations squad, with Test rookies like Cameron Winnett and Alex Mann performing impressively during narrow defeats against Scotland and England.

Bath prop Archie Griffin joined them in making an international debut during the tournament, and 20-year-old Cardiff forward Mackenzie Martin will follow suit if he features off the bench this weekend.

And while Wales might no longer have the services of players like Halfpenny, Louis Rees-Zammit and Dan Biggar available – or, for the current Six Nations, injured trio Jac Morgan, Dewi Lake and Taulupe Faletau – green shoots are evident.

Thomas added: “We have lost a lot of senior boys, which is always difficult, but I am enjoying trying to help the younger boys who haven’t had that experience yet.

“We have got a group of young boys who are listening, learning and working really hard, so there is a good energy about the place.

“It is such a fine margin in terms of getting those two games to be wins (Wales lost to Scotland and England by a combined margin of three points).

“Give us those two wins, and we are in a very good place.

“The amount of effort that has gone into those first two games, we are going to need the same again, but close the game off a little bit better as well.”

Flanker James Botham has been released from Wales’ Guinness Six Nations squad due to a knee injury.

The Welsh Rugby Union said that Botham, who is the grandson of England cricket great Sir Ian Botham, was hurt during Saturday’s 27-26 defeat against Scotland.

Cardiff forward Seb Davies has been called into the squad, while experienced Harlequins prop Dillon Lewis has also been summoned by Wales head coach Warren Gatland ahead of next Saturday’s Twickenham appointment with England.

The WRU said: “James Botham (Cardiff Rugby) has been released from the squad due to a knee injury picked up during Wales’ 26-27 defeat to Scotland on Saturday.

“He will continue his rehabilitation back at his club.”

Botham scored Wales’ opening try during a thrilling second half against the Scots that saw them fight back to within a point after trailing 27-0.

His Cardiff team-mate Alex Mann, who also touched down, replaced him on his Test debut and now looks a likely starter against England.

Botham’s problem is another back-row injury blow for Gatland, with World Cup co-captain Jac Morgan and 104 times-capped number eight Taulupe Faletau out of the tournament.

Lewis, who has won 54 caps, was a surprise omission from Gatland’s original Six Nations squad.

And he now becomes the fourth tighthead in the group, joining Leon Brown, who started against Scotland but went off at half-time due to an injury, Keiron Assiratti and uncapped Bath forward Archie Griffin.