A stack of injuries in the opening weekend's action at the World Cup has underlined how important squad strength will be in deciding which teams will go deep into the marathon, six-week tournament.Among those paying the price of the increased physicality in the game were Argentinians Gonzalo Tiesi, who was ruled out of the rest of the competition with a knee injury, and fly-half and skipper Felipe Contepomi who has badly bruised ribs.The Pumas have brought in Lucas Borges to replace Tiesi with the former Stade Francais winger arriving at the team's Dunedin base on Tuesday after flying in from Buenos Aires.Reigning champions South Africa saw veteran lock Victor Matfield (hamstring) and centre Jean de Villiers (ribs) both ruled out for 10 days while David Skrela (shoulder) and Fabrice Estebanez (back) are big worries for France.Australia winger Digby Ioane could be forced to pull out of the tournament with a thumb injury while Ireland prop Tony Buckley was having a scan on his shoulder.Influential New Zealand backrower Kieran Read has been sidelined since last month with a bad ankle sprain which has forced him to wear a moon boot for support.The 32-Test 25-year-old is an integral part of the All Blacks' premier loose trio with Richie McCaw and Jerome Kaino, moving coach Graham Henry to admit before the World Cup that he was "praying" for a rapid recovery.But Read said he was on track to have one game under his belt before the play-offs.Particularly hard-hit have been Japan whose number eight Ryukoliniasi Holani has been ruled out for the tournament, alongside New Zealand-born lock Justin Ives who failed to recover from a knee problem.Brave Blossoms skipper Takashi Kikutani admits that the loss of the two would be a blow, but he was hopeful their replacements -- Yuji Kitagawa and Toetsu Taufa -- would compensate for the loss."It's tough not having Justin and Holani around any more. But Kitagawa and Taufa are good players as well and they can give us a lift. We just need to communicate, look after each other," he said.Kitagawa will be playing in his second World Cup and he believes that his greater experience will stand him in good stead."I wasn't thinking about the national team at all," he said. "I saw the opening game on TV, but never expected to be here. I feel like I'm a bit behind the rest of the squad, but I was with the team in June, July so I'm not that concerned.Conscious of the pounding taken by his players in their 34-24 win over Romania, Scotland coach Andy Robinson has rung the changes for Georgia in Invercargill on Wednesday with only four players being retained in the starting XV."It's very difficult for the players to play two games in four days," he said."Whilst we're asking a number of players to do that, (considering) the strength of the squad that we've got and the depth of the squad that we've got, (we're) looking at the personnel that we've selected to perform against Georgia."