Former world number one Tiger Woods will on Monday drop outside the top 100 in the rankings for the first time in more than 18 years.

The 39-year-old American is down at number 96 and a world ranking official told Reuters that he is likely to slip to 102nd when the list is adjusted after this weekend's tournaments.

Woods posted an 82 at the Phoenix Open in January, his worst round as a professional, as he slumped outside the leading 50 in the rankings for the first time in more than three years.

Since then the 14-times major winner has continued a downward slide that resulted in him failing to qualify for this month's WGC-Cadillac Championship, an event he has won seven times.

Woods was ranked 433rd when he turned professional in September 1996.

He then jumped to 75th after landing his first victory as a professional at the 1996 Las Vegas Invitational, the first of 79 PGA Tour titles.

Woods first moved to world number one when he finished 19th at the 1997 U.S. Open.

The American spent a record total of 683 weeks at the top of the rankings until he lost the number one spot to Australia's Adam Scott in May 2014.

Current number one Rory McIlroy has been top of the rankings since August.