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Canadian pop-punk act Sum 41 has been forced to cancel their return to the Vans Warped Tour. The band had played over 20 dates this season before taking a leave to play Japan's Summersonic Festival. In Japan frontman Deryck Whibley was attacked in what's being described as a "random unprovoked incident," which has aggrevated a slipped disk injury that he sustained in 2007. While the band chose to perform the festival in Osaka and Tokyo despite the injury and advice of doctors, Whibley's condition has not improved. Drummer Steve Jocz commented:

Being a part of the Warped Tour this summer meant a lot to us. We haven't toured in two years and the bands, the crowds and the entire Warped Tour crew have been amazing to us. We were excited to be back in front of our fans and are very disappointed that we have to pull off the tour. We know that it would be more frustrating for the fans if we can't give it our all. Deryck is doing everything he can to get himself better and we're there for him.