WIMBLEDON, England -- The defending champion comes in at something less than 100 percent, for it’s been a rough month for Elena Rybakina.

She was already struggling with allergies at Roland Garros when her weakened immune system was further compromised by a viral illness. Rybakina withdrew from her third-round match and spent the next several days in bed.

She got on the court a few weeks later in Berlin but lost her second match to Donna Vekic. A week ago, still feeling under the weather, she withdrew from the tournament in Eastbourne.

Wimbledon: Scores | Draws | Order of play

“The preparation we did, I would say it was good, but still not the amount of hours and work we wanted to put in,” Rybakina said Sunday at Wimbledon. “But overall, I think we did maximum what we could. It’s been tough.”

A year ago, Rybakina was not a name most casual tennis fans could invoke. Ranked No.23 among Hologic WTA players, she had reached only one major quarterfinal, Roland Garros in 2021. And then she tore through the Wimbledon field, defeating Ajla Tomljanovic, Simona Halep and Ons Jabeur in her last three matches.

Rybakina, who turned 24 a few weeks ago, has developed a rare affinity for the lush lawns of the All England Club. She’s 10-1 in her first 11 Wimbledon matches -- only Billie Jean King (11-0) was better in the Open Era.

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Among women with a minimum of 10 matches here, Ann Jones (12-1) holds the highest winning percentage (92.3). With a victory Tuesday over Shelby Rogers and then the winner of Alize Cornet and Nao Hibino, Rybakina would equal that epic start.

At six feet, Rybakina has a power game that flourishes on grass. It starts with her serve. A year ago, she stroked a tournament-high 64 aces. Her fastest, at 122 mph, was surpassed only by Coco Gauff’s 124. Rybakina leads the WTA Tour with 315 aces this year, not all that far from her 2022 total of 380.

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She’s won 31 matches for the year, trailing only No.1 Iga Swiatek (38) and No.2 Aryna Sabalenka (35). With Russian and Belarusian players banned last year, Rybakina did not receive credit for the 2,000 ranking points that come with winning a major.

Still, she persevered, reaching the finals in Melbourne earlier this year and rising to a career-high No.3 in June.

“It was last year, so I don’t really think about it so much,” Rybakina said. “Now I have another opportunity. It’s going to be exciting for me. Yeah, to play now first matches on big courts, it's different for me. Also to come to the tournament as a defending champion, it's something new.

“Yeah, hopefully I’m going to win.”

Here are some of the notable Tuesday matches from the loaded bottom half of the draw:

No.3 Elina Rybakina vs. Shelby Rogers

The macro analysis is heavily in Rybakina’s favor. Only once has a Wimbledon women’s champion lost in the opening round the following year; in 1994, Steffi Graf was upset by Lori McNeil. In her past 13 Grand Slam openers, Rybakina has lost only once, to Clara Burel at last year’s US Open.

At the micro level, however, it’s a different story. Rybakina holds a narrow 3-2 edge in a head-to-head series that features three grass meetings. Rogers won the last one a year ago in s- Hertogenbosch -- in straight sets.

Rogers, ranked No.46, is 14-12 for the year. She’s coming off three straight losses on clay -- Madrid, Rome and Paris -- and hoping the move to grass will change the narrative. She’s reached the second round only twice in six appearances and has lost six straight matches to players ranked in the Top 10.

No.2 Aryna Sabalenka vs. Panna Udvardy

As the fortnight progresses, keep this little trend in the back of your mind: Sabalenka has produced her best career effort in each of the year’s first two majors. She won her first Grand Slam singles title at the Australian Open and reached the semifinals at Roland Garros, falling to Karolina Muchova 6-7 (5), 7-6 (5), 7-5.

“It was a good lesson for me,” Sabalenka said before Wimbledon. “No matter what, I have to keep trying -- just not losing it easily, you know? Just keep trying things. Not going crazy on court. Understand that no matter what happened, I still have a lot of chances.”

Easier said than done, but the 25-year-old Sabalenka has increasingly showed an ability to navigate her way through difficult moments.

Udvardy, a 24-year-old from Hungary, is ranked No.82. She’s 8-11 in singles this year but recently reached the final of a WTA 125 in Spain.

These two have never played.

No.10 Barbora Krejcikova vs. Heather Watson

She’s a Grand Slam champion in singles and doubles and a former World No.2, but grass remains a bit of an unknown quantity for Krejcikova.

She’s advanced to at least the quarterfinals of the other three majors but never past the fourth round at Wimbledon. This is only Krejcikova’s third appearance at the All England Club.

As a player from Great Britain, Watson is quite familiar with the concept of grass. This is the 31-year-old’s 13th outing at Wimbledon, although she’s only 11-12 overall. Watson, who received a wild card, is coming off a terrific run in Nottingham. After winning two qualifying matches, Watson scored three more victories before falling to eventual champion Katie Boulter.

This is their first meeting.