"He might be sick. Maybe there's incredible wind, rain, 10 rain delays."
Roger Federer might have 20 Grand Slams to his name, but the Swiss knows he faces an almost impossible task in the French Open semi-finals - beating Rafael Nadal.
The defending champion, dubbed the 'King of Clay', is eyeing a record-extending 12th title at Roland Garros and has only lost two of 93 matches since his debut in Paris in 2005.
So what chance does Federer, whose only French Open title came a decade ago, have of beating Nadal in the last four?
"Like against any player, there is always a chance," said the 37-year-old.