Mark O'Meara, the 1998 Masters champion, withdrew with a rib injury before his first round at Augusta National.
The PGA Tour said O'Meara was forced out when he pulled a muscle. He had played a practice round with good friend Tiger Woods the day before, and then took part in the Par 3 contest.
He has not made the cut at Augusta National since 2005, when he finished tied for 31st. He is a two-time major champion, also winning the British Open in 1998.