Cardiff - Wales coach Warren Gatland has called on his side to “send a message” to their Rugby World Cup rivals by beating England at the Millenium Stadium on Saturday.The match will be the second game between the two Six Nations teams in as many weeks, after the Wales lost the reverse fixture 23 – 19 at Twickenham last Saturday.According to Gatland, victory in the game is vital to building up the confidence his team will need to to reach their top form during the World Cup.“We have spoken as a group about how important it is for us to win at home. We have done a lot of hard work as a squad in the last few months,” Gatland is reported to have said on Wales Online.“But, if we want to be serious World Cup contenders, we need to send out a message that we are good enough to beat England and Argentina at home. It will build up our confidence and send a message to other nations ahead of the World Cup.“I don’t want us going to New Zealand with people thinking Wales beating other nations is going to be a surprise or an upset. I want people to think when we take the field, we are good enough to beat anyone. That is why winning on Saturday is so important.”Gatland has made only four changes to the line-up that lost to England last weekend - one of which was forced - in hope that selection continuity will ease the teams path to victory.In the backline, James Hook has replaced fullback Morgan Stoddart, who left the pitch with a broken leg last week, and Gavin Henson will start at inside centre in place of Jamie Roberts, who supplants Jonathan Davies at 13.While in the forward pack, hooker Lloyd Burns displaces Huw Bennet and Luke Charteris replaces Bradley Davies in the second row.The team have been put through a punishing training schedule during the preseason and visited Poland twice for intense training camps in July.Wales have been grouped with minnows Namibia, Pacific Islanders Fiji and Samoa, and defending champions South Africa in Pool D of the tournament.Wales and England have one more warm up game each, against Argentina and Ireland respectively, before the World Cup starts in September.