Essential News from The Associated Press 1, 2013 9:40 AM ET Singh out of tournament, day after exonerated By DOUG FERGUSONBy DOUG FERGUSON, AP Golf Writer Vijay Singh, of Fiji, tees off on the ninth hole while wearing a "Els for Autism" ribbon in his visor during the second round of the RBC Heritage golf tournament in Hilton Head Island, S.C., Friday, April 19, 2013. Tournament organizers teamed up with the Els for Autism nonprofit organization to highlight the importance of early detection. AP Photo/Stephen Morton PGA Tour Commissioner Tim Finchem appears during a news conference, Tuesday, April 30, 2013, in Charlotte, N.C. The PGA Tour dropped its doping case against golfer Vijay Singh on Tuesday based on new information from the World Anti-Doping Agency, which said using deer antler spray is no longer prohibited because it contains such small amounts of a growth hormone factor. Vijay Singh walks off the practice putting green prior to a practice round for the PGA Tour Wells Fargo Championship golf tournament in Charlotte, N.C. on Tuesday, April 30, 2013. The PGA Tour dropped its doping case against Vijay Singh on Tuesday based on new information from the World Anti-Doping Agency, which said using deer antler spray is no longer prohibited because it contains such small amounts of a growth hormone factor. AP Photo/The Charlotte Observer, Jeff Siner CHARLOTTE, N.C. (AP) - Vijay Singh has withdrawn from the Wells Fargo Championship, citing a sore back. Singh pulled out of the tournament one day after the PGA Tour said it would not punish the 50-year-old Fijian for his admission that he used deer antler spray. The tour said the World Anti-Doping Agency informed it that spray contains only small amounts of a substance that is banned under the anti-doping policy. The tour had been set to sanction Singh until WADA clarified its position on deer antler spray on Tuesday. Singh is a past champion at Quail Hollow.