AUCKLAND, New Zealand—The groin injury that ended Dan Carter's Rugby World Cup on Sunday has wreaked havoc on New Zealand's hopes of winning the tournament and caused untold angst in this country of four million.

But here's what hasn't been said: The loss of the All Blacks' superstar playmaker may be a bigger blow for a tournament that has been sorely lacking in star power.

Through the end of group play Sunday, the players who were supposed to dominate the World Cup—guys like Australia's Quade Cooper, New Zealand's Richie McCaw and England's Jonny Wilkinson—have fizzled, while the runaway stars of the tournament so far are a collection of obscure names almost nobody had tabbed as gamebreakers a few weeks ago.

This is partly down to the nature of this event. The Rugby World Cup, more than perhaps any other international tournament, is a war of attrition. With 48 games spread across seven weeks, star players are often rested for group matches as teams attempt to pace themselves for later rounds.

"If I had to play in a knockout game I would have, but the decision was made to make sure I'm right for next week," McCaw, the All Blacks captain, said of his absence from New Zealand's final group game against Canada with a foot injury. (He also missed the country's first-round win over Japan.)