 Montgomerie was forced to miss a pro-am earlier this week |
Colin Montgomerie is the second big name to pull out of the BMW International Open in Munich, which starts on Thursday. The Scot, who missed the cut at last week's US Open, flew to Canada on Monday for a pro-am but fell ill on the journey back to London.
"He was sick overnight Tuesday and all day Wednesday," said Montgomerie's manager Guy Kinnings.
American John Daly pulled out on Wednesday citing "personal reasons".
Daly alleged two weeks ago that his wife had tried to attack him with a steak knife and he told BMW International Open organisers that he "could not currently leave the United States".
Montgomerie had been due unveil his third caddie in three weeks after splitting from Alastair McLean following his missed cut in the Austrian Open.
Kinnings said around 30 names for a permanent replacement had been drawn up and a decision would be made before next week's French Open.
Montgomerie's place in Munich has been taken by England's Shaun Webster.