PARIS: Thanks to rain, Novak Djokovic and Serena Williams must wait an extra day to start their bids for history at the French Open.

The two No. 1-seeded players originally were slated to play first-round matches on Monday, the second day of the clay-court Grand Slam tournament.

But the schedule already is being shuffled because of showers that created a delay of more than 2½ hours in the afternoon and returned to halt all play in the early evening, allowing a total of only 10 out of 32 matches to be completed.

So the soonest Djokovic — who is trying to complete a career Grand Slam and become the first man since Rod Laver in 1969 to win four consecutive major titles — and Williams — hoping to equal Steffi Graf's Open-era record of 22 major championships — will get started is Tuesday, which is Day 3 at Roland Garros.

Instead, some of the players considered possible challengers will be in action on Monday. If the weather holds up, that is, because there is more rain in the forecast for Day 2.

Among those scheduled to play Monday: No. 3 Stan Wawrinka, the defending champion, who beat Djokovic in the 2015 French Open final.

"Novak is the favorite, for sure," Wawrinka said. "But I think it's going to be interesting to see what's going to happen with the other players."

Wawrinka is coming off a confidence-boosting title last week on red clay in Geneva, where he defeated his first opponent in Paris, Lukas Rosol, in the semifinals.

That victory made Wawrinka 4-0 against Rosol, a player best known for stunning Rafael Nadal in the second round of Wimbledon in 2012.

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

Murray starts: No. 2-seeded Andy Murray's first-round match comes against Radek Stepanek, who qualified for the main draw at the age of 37. They've played eight times in the past, dating to 2005, and Murray is 6-2 in those matches. Murray is coming off a clay title at the Italian Open, where he defeated Djokovic in the final. Murray is also without a full-time coach at the moment, having recently split with Amelie Mauresmo. "I had the impression that we'd reached the end of what we could do professionally together," Mauresmo said in an interview with L'Equipe magazine. "Andy is complex. On a court, he can be the opposite to how he is in life. It can be disconcerting." As for when he'll hire a replacement, Murray said: "Things obviously are going well just now, so no need to sort of rush into anything."

Top women: Some past Grand Slam runners-up who hope to supplant Williams as the champion in Paris get their tournament started, including No. 2 Agnieszka Radwanska against 120th-ranked Bojana Jovanovski of Serbia, No. 4 Garbine Muguruza against 38th-ranked Anna Karolina Schmiedlova of Slovakia, and No. 6 Simona Halep against 71st-ranked Nao Hibino of Japan. Radwanska lost to Williams in the Wimbledon final in 2012, Muguruza did the same last year, and Halep lost to Maria Sharapova in the French Open final in 2014.

Resuming: The half-dozen matches that were suspended in progress Sunday are to resume Monday. Those involve players such as No. 5 Kei Nishikori, who has a two-set lead against Simone Bolelli; No. 23 Jack Sock, headed to a fifth set against Robin Haase of the Netherlands; and 2009 French Open champion Svetlana Kuznetsova, up a break at 3-1 in the third set against Yaroslava Shvedova.