Sergio Garcia, Bob May and Nick Faldo were added to the field for next month's World Match Play championship at Wentworth, England.
Lee Westwood, Darren Clarke, Padraig Harrington, Retief Goosen and Adam Scott are the other unseeded players.
Colin Montgomerie, Ernie Els, Thomas Bjorn and Vijay Singh were seeded for the $1.5 million event earlier.
The eight unseeded players will play four 36-hole first-round matches on Oct. 5. The winning four will go on to play the seeded players the next day, and the semifinals and finals are scheduled for Oct. 7 and 8.