Lock Luke Charteris says Wales cannot afford to repeat their poor Six Nations start at the 2015 World Cup.
Had they beaten England in Cardiff in their Six Nations opener, Warren Gatland's side would have gone to Italy seeking a Grand Slam.
"We have to work on that first game," said Racing Metro's Charteris.
Wales will be expected to beat Uruguay by a big margin in their Pool A World Cup opener at Cardiff's Millennium Stadium on Sunday, 20 September.
Warren Gatland's side then go to Twickenham to face tournament hosts England six days later.
Games against Fiji (1 October, in Cardiff) and Australia (10 October, Twickenham) complete Wales's group games.
Chateris added: "The pool we've got in the World Cup is so tight, you can't really afford to start slowly.
"If you lose one of the games, then you're out of the tournament.
"So that's something we'll have to look at."
Gatland has highlighted Wales' tendency to start tournaments slowly and improve as they progress - as was the case in the 2013 and 2015 Six Nations.
Wales lost to Ireland in their 2013 opener in Cardiff and went on to storm to the title with a 30-3 win over England on the final day in the same city.
Charteris believes Wales will benefit hugely from a longer preparation time in the World Cup build-up.
Wales will train in the heat of Qatar and at a high-altitude camp in Switzerland ahead of the tournament.
"We'll obviously be together for a long time before the World Cup, which is the advantage of it," said Charteris.
"In the Six Nations you come in and you're only together a week or a week-and-a-half so it takes time to bed in.
"In the World Cup, we'll have a few months together.
"So hopefully that won't be a problem and we'll hit the ground running."