Shane Williams has urged Wales' World Cup hopefuls to be more "confident and arrogant" going into the tournament in Japan.
Warren Gatland's side face England at Twickenham on Sunday, 11 August, in their first warm-up match before the Japan tournament in the autumn.
After a record 14 successive wins, including the 2019 Six Nations title, Wales are among the favourites.
"You've got to talk yourselves up sometimes," said wing legend Williams.
The former Ospreys and British and Irish Lions star's 87-cap Wales career included playing at the 2003, 2007 and 2011 World Cups.
He helped Wales reach the semi-finals in New Zealand in 2011 before making an emotional farewell against Australia in December of that year.
'Weird situation'
Williams says Wales find themselves in an unusual position ranked second in the world and being among the favourites for the 2019 title.
"Perhaps the likes of Australia, New Zealand aren't playing particularly well, but that doesn't matter for those guys," Williams told Radio Wales Breakfast with Claire Summers.
"They will certainly turn up and be one of the favourites for the cup, but as far as Wales are concerned they're in quite a weird situation for Wales.
"We've been targeted as one of the favourites for the World Cup and never been in that position before as a nation.
"But I think it's great. I think the players, squad and coaches we have at the moment need to be a little bit more confident and need to be a little bit more arrogant about how good they can actually be going into this World Cup because it will give them massive confidence.
"That's why a lot of these games prior to the World Cup are so important.
"You're playing England and Ireland, potential World Cup winners and some of the best teams in the world."
Wales host England on Saturday, 17 August before two games against Ireland on Saturday, 31 August in Cardiff and Dublin a week later.
England and Ireland were among Wales victims during a Six Nations in which Gatland saw his team extend the nation's record winning streak to 14 games.
'Take it all the way to Japan'
Williams and former England centre Jeremy Guscott tipped Wales to win the World Cup on BBC Radio Wales.
Williams bases his belief on "the fact they're on this winning streak now. The fact they're playing some good rugby; there's players on form - the likes of Alun Wyn (Jones), (Justin) Tipuric, Liam Williams as well, who's had a fantastic season - take that confidence with you on the weekend.
"Take it all the way to Japan with you and believe in yourself."
The All Blacks, Wallabies, South Africa and Argentina are involved in their annual Rugby Championship in the World Cup build-up, a factor not lost on Williams.
South Africa are on top after two rounds, with two more left.
"Perhaps New Zealand, Australia and South Africa are playing some good rugby, but they're not on top form at the moment," said Williams.
"But they are playing rugby now and that's what we've got to keep an eye on - how well they go prior to the World Cup starting.
"We've got to be very confident."