Australian Jason Day has followed former winner Mark O'Meara in pulling out of next week's Open Championship.
Day was runner-up in both The Masters and US Open last year.
The 24-year-old's wife gave birth to their first child on Tuesday and Day has decided to stay at home with his son Dash.
Reigning US Open champion Webb Simpson is expected to follow as his wife is expecting their second child in a fortnight.
There will be no replacements until the field size drops below 156 and it could be at 158 if the spots available at this week's Scottish Open and John Deere Classic are claimed on Sunday.
