Best wants Ireland to explode in Japan and have no regrets

The captain is unlikely to be involved in this weekend's first warm-up game against Italy, but he says the squad are working hard towards producing a strong performance in their opening fixture in Yokohama to inject momentum into their campaign.

Expectations for the tournament have been dampened after Ireland's form took a turn last spring, but Best believes they can disprove the theory that they showed their best form too early during their all-conquering run in 2018.

Approaching his fourth World Cup, Best wants to leave Japan without the regret he experienced in 2007, 2011 and 2015.

"You try to avoid it, but you can't. People are saying we peaked in 2018, that we did this, that and the other, or we're predictable," he said.

"If we can get ourselves in the next four (warm-up) games into a position where we can explode into the tournament on September 22, I think that will speak volumes about the job the coaches have done, but also the job this leadership group has done. That is the big thing. Just to make sure that we're in the best possible place because, like for me, I'll never get another opportunity.

"Some boys might not get another opportunity, some are young enough and they will. So for me, it's to make sure, like most of the questions were about '07, '11 and '15, and the learnings and regrets.

"I'll carry those, you could ask me in 40 years and I could give you the exact same answer because, when you're at this level, those regrets will stay with you forever and that is ultimately what I don't want."

Having reflected on the Six Nations disappointmented, Best believes that the team became complacent after a remarkable 2018 campaign.

"Probably subconsciously, in the 2019 Six Nations we maybe did. I don't think it was anything conscious, but when you look back now we probably believed that we had the ability to turn up and beat anyone. That we were this all-conquering force having won the Grand Slam, the Australia tour, beaten the All Blacks and Argentina.

"It's funny how those little things go through your head. Maybe, at this level, it's not doing that extra couple of minutes on the computer tonight. I'll look at training, but skip a bit."