Reigning Masters champion Danny Willett has withdrawn from this week’s Arnold Palmer Invitational because of illness.
The 2017 Masters begins in three weeks at the Augusta National in Georgia.
The Englishman, who won his first major by three shots, is scheduled to play in next week’s WGC Match Play in Texas.
Willett, the world number 14, said on Twitter: “I’ve been up all night with terrible sickness. Not ideal but felt it worse to take a spot from the first reserve if I wasn’t able to finish.”
The 29-year-old was replaced in the field at Bay Hill by American Blayne Barber.
Willett was fifth in the Maybank Championship in February after failing to convert a three-shot lead after three rounds, but then missed the cut in the Honda Classic and was 69th in a 77-man field in the WGC-Mexico Championship.
Coverage: Watch live on the BBC, BBC Sport website and the sport app, listen on Radio 5 live and Radio 5 live sports extra
Masters champion Danny Willett says Muirfield voting to admit women members for the first time is a “great thing”.
Members at the privately owned golf club voted 80.2% in favour of updating its membership policy on Tuesday.
Golf’s ruling body, the R&A, removed Muirfield as a host venue for the Open Championship after it chose to maintain the ban in 2016.
“It shows how times have changed, it shows golf has changed,” said Englishman Willett.
“When the vote was passed that females weren’t going to be allowed and they were going to be taken off the Open rota, it was not only a blow for a lot of other things, it was a blow for us golfers who think that golf course is one of the best Open courses.
“It’s a great thing that they’ve done.”
Willett, 29, will defend his Masters title at Augusta between April 6-9.
Last April, he claimed his first major by three shots on five under par, becoming the first British winner since Sir Nick Faldo in 1996, but has struggled recently and says his form is “nowhere near” what it was.
He does not expect a backlash from American fans after he was forced to apologise last September for an article written by his brother, Peter, in which he called American Ryder Cup fans a “baying mob of imbeciles”.