Keith Earls is, like most of the Ireland players, in a good place right now.

The Munster man missed the Rugby World Cup Pool A opener against Scotland with a thigh problem but he insists "the body is feeling really good now" after a good week in camp.

The mood has been transformed by crucial warm-up wins against Wales - after that Twickenham mauling had raised serious questions about the Irish - and an impressive defeat of the Scots.

Earls should get his first taste of World Cup action against Japan this Saturday morning. It's a chance he's ready to grab with both hands.

"It has been frustrating for me during pre-season between knee and back issues, but that's the joys of it I suppose," he told RTÉ Sport's Michael Corcoran.

"My workload had been up massively from the pre-season the year before so I can take confidence out of that.

"This week has been quite positive but there is a good bit to work on. Thankfully I'm ready to go. I'd a full training session (on Tuesday) so, happy out.

"It was a tough game. The Scots always put up a massive challenge. We put a nice score on them as well.

"Momentum is building. We'd two good wins against Wales before leaving for Japan. The weeks are a lot better when you're winning. They're easier to get through. All the boys are buzzing. Everyone wants to play. We're in a good place but we know we can still improve."

"The humidity is what it is. We just have to get on with it, push through the pain barrier of sucking a bit of diesel and sweating a bit."

Next up is a clash with the host nation in Fukuroi City, where the weather is forecast to be overcast but very humid. 

Earls played in the two-Test series in Japan back in 2017 so he has an idea of what to expect. It will be a slog.

"Every time you play against Scotland you're going to be sucking a bit of diesel," he said when asked about the impact of the conditions on the players.

"The humidity is what it is. We just have to get on with it, push through the pain barrier of sucking a bit of diesel and sweating a bit.

"Luckily for me and a few of us - James Ryan, Jack Conan - there's a good few of us that were here in 2017. We know what the Japanese are all about. They are an extremely fit team, they're well coached, well drilled and they play a massively high tempo game.

"It's going to be a completely different challenge for us. We definitely have to be on top of our game again."

Follow Ireland v Japan on Saturday (kick-off 8.15am) via the live blog on RTÉ.ie/Sport andthe NewsNowApp, watch live on RTÉ2 from 7.30am or listen to live match commentary on RTÉ Radio 1.

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