MADISON, Miss. (AP) -- Sean O'Hair and Rory Sabbatini are among the latest PGA Tour players to commit to playing in next week's Viking Classic at Annandale Golf Club. Tournament director Randy Watkins says Vijay Singh has turned down an invitation to the tourney. The Viking Classic, beginning September 18th, will pay $648,000 to the winner from a 3.6 million dollar purse. Players have until 5 p.m. Friday to commit to the tournament. They can withdraw at any time.