O'Meara last communicated with Woods about three or four weeks ago by text and knew of the 14-time major winner's plans to split with Williams after 12 years. O'Meara and Woods have been close friends for more than a decade.
"They had a great run together as a team. Steve Williams is a loyal guy but Tiger is Tiger," O'Meara said, speaking after the first round of the Senior British Open at Walton Heath in south England.
"For a caddie, there's not much better than Steve Williams. But as good as Tiger can play at times, he doesn't need a whole lot of help out there."
Information from The Associated Press was used in this report.