John Isner is all too aware of his lack of success in fourth-round matches at Grand Slam tournaments: 1-5.

To reach the second major quarterfinal of his career — and first at the French Open — the 31-year-old American will need to do something he's never done, not even once, in five tries: beat Andy Murray.

"I have definitely fallen in the round of 16 quite a bit," the 15th-seeded Isner said. "We will try to correct that going forward."

His latest attempt to get past No. 2 Murray is scheduled for Sunday, when the forecast calls for plenty of rain.

"I know I'm going to have my hands full," the big-serving Isner said about the matchup against Murray, a superb returner, "but I think Andy will have his hands full, as well."

Aside from what's at stake for Isner personally, he also can become the first American man to get to the quarterfinals at Roland Garros since Andre Agassi did it 13 years ago.

The last time any man from the United States was a quarterfinalist at any Grand Slam tournament was in 2011, when Isner and Andy Roddick got that far at the U.S. Open.

"It's definitely not the American tennis of the early 2000s or '90s," Isner said, referring to a generation that included Agassi, Pete Sampras, Jim Courier and Michael Chang. "I have been (the) No. 1 American for a long time now — generally around 14, 13 in the world, which I'm very proud of. But it's not the same. It's not what American tennis fans are accustomed to."

In his previous match, a straight-set victory over 6-foot-11 (2.11-meter) Ivo Karlovic, Murray got a sort of dry run for facing the 6-foot-10 (2.08-meter) Isner. Showing how well he can neutralize a top server, Murray broke Karlovic twice in a row at the outset.

"Definitely got some reps in against a pretty big serve. I would have rather him played a grinder," Isner said, before noting that he and Karlovic are not exactly the same player.

"My serve is a little bit different," Isner said. "I think I can back it up better, as well."

Murray's comparison between the two opponents?

"John plays a bit more from the baseline, a bit more consistent from the back of the court. ... Doesn't volley as well," said Murray, a two-time major champion and a three-time French Open semifinalist. "I mean, they're obviously both two big guys with great serves, but they are quite different, really, in the way that they play and the way they hit the ball."

Here's a look at what else is happening at the French Open on Sunday:

ROGERS EYES QUARTERS: American Shelby Rogers and her opponent, No. 25 Irina-Camelia Begu of Romania, are the only two women on their half of the draw who never have reached a Grand Slam quarterfinal. The 108th-ranked Rogers, who is from South Carolina, had never even been past the third round at a major until now. Rogers credits her older sister, who played college tennis and now is a psychologist, with providing helpful tips about the mental side of the sport. "She tries to keep me in the moment," Rogers said, "not thinking about too many things in the past or too many things in the future."

RAONIC AND MCENROE: Eighth-seeded Milos Raonic of Canada has a new consultant on his side: seven-time major champion John McEnroe. They were out on a practice court together Saturday, and Raonic — who meets 55th-ranked Albert Ramos-Vinolas in the fourth round — plans to have McEnroe's assistance during grass-court preparation for Wimbledon.

OTHER MATCHUPS: The other men's fourth-round matches are defending champion Stan Wawrinka vs. No. 22 Viktor Troicki, and No. 5 Kei Nishikori vs. No. 9 Richard Gasquet. The women's: No. 2 Agnieszka Radwanska vs. Tsvetana Pironkova, No. 4 Garbine Muguruza vs. 2009 champion Svetlana Kuznetsova and 2014 runner-up Simona Halep vs. 2010 runner-up Sam Stosur.

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