Rafael Nadal winning a 10th French Open would be "one of sport's biggest achievements", says former British number one Tim Henman.
The Spanish fourth seed is into round three after outclassing Dutchman Robin Haase 6-1 6-4 6-3 on Wednesday.
The 30-year-old would become the first player in the Open era to win 10 titles at one Grand Slam, should he progress.
"It would be such an incredible achievement by such an incredible player," said Henman.
"You can't even fathom it. A lot of people don't win 10 tournaments, let alone 10 Grand Slams at one venue," added the Englishman.