Roger Federer hailed Rafael Nadal's barnstorming return to duty as "amazing" on Friday before turning his attentions to his own ironman efforts which see him playing in a 54th consecutive Grand Slam.
Nadal, bidding for an unprecedented eighth French Open title, is the overwhelming favourite, having won six titles in eight finals since resuming his career after a seven-month injury lay-off.
"His level of play compares to what he's done always. I think the results show how good he's playing. It's nice to see him so strong," said Federer who got a close-up of that strength in a Rome Masters final mauling last weekend.
That took his career record against Nadal to 10 wins against 20 losses.
"You know, eight out of eight finals of eight tournaments. It's amazing. I'm sure he's very happy, and super confident going into the French Open."
Federer won the title at Roland Garros in 2009, the year when Nadal suffered a shock fourth round loss to Robin Soderling -- still his only defeat in 52 matches on Paris' red clay.
Nadal went on to skip Wimbledon that year, tearfully renouncing his All England Club title.
The Spaniard's second round defeat to Lukas Rosol at Wimbledon last year then meant more rehabilitation with Nadal missing out on the Olympics, US Open and Australian Open as he spent seven more frustrating months nursing his knees.
"He only came back when he was 100%. I mean, looking back, he did all the right decisions to take his time. He's healthy, he's fit, hopefully in no pain. Then can he also keep it up on other surfaces? That will be the next question for him."
By comparison, Federer, with his 32nd birthday fast approaching, has enjoyed a relatively injury-free career and this French Open will be his 54th successive major, putting him just two behind the record held by South African Wayne Ferreira.
"It's incredible. I never thought I was going to play that many, have that many opportunities to do well at the Slams. I'm happy about it, but they don't buy me victories," said Federer.
"But it shows great stamina. In a Slam, where you know you're going to enter best of five set matches over two, three weeks, you have to be at your best and you need to feel like you can compete with the best at the highest of levels for a long period of time.
"There is no shortcut in best of five set matches, and that's where I think I was always up for the challenge. I'm very happy that I was able to do that for so long so far."