Serena Williams breezed past Rebecca Peterson on Monday. (Adam Pretty / Getty Images)

Pain from a lingering knee injury forced Serena Williams to withdraw from a third straight tournament Tuesday, pulling out of the Italian Open the day before she was to play her sister, Venus Williams, in the second round.

She will prepare for the French Open, which begins May 26, with precious little clay-court competition, having completed only one match, a 6-4, 6-2 victory Monday over Rebecca Peterson, in the three tournaments. Williams has won the French Open, the second Grand Slam event of the year, three times (most recently in 2015).

“I must withdraw from the Italian Open due to pain in my left knee,” Williams said in a statement. “I will miss the fans and competition at one of my favorite tournaments. I’ll be concentrating on rehab and look forward to seeing you all at the French Open and next year in Rome.”

She withdrew from the Miami Open before her second match because of the knee injury and retired during her second match at the Indian Wells tournament this spring because of a viral illness. She has lost only once this year, falling to Karolina Pliskova after rolling her ankle on the first of three match points in the quarterfinals of the Australian Open. But Williams has played only nine matches in 2019 and said that “it felt good to be back in the match” after beating Peterson.

“It’s been awhile. I haven’t played a ton of matches this year,” she told reporters afterward. “Not my choice, just by force. I really, really, actually desperately wanted to be on the tour and to be playing, but it hasn’t been able to work out.”

She admitted that she had been out “much longer” than she expected and that the injury limited her ability to train.

“I’ve just been on this diet basically; it’s been awful. When you’re sedentary, it becomes hard to manage your body. So it’s just basically you have to eat grass. That’s kind of what I did,” she said. “It was a nightmare. But it worked and it paid off. I didn’t get to train too much. It’s more the process. I feel like I’m taking it one day at a time — I’ve been really putting in the hours in terms of keeping my cardio as much as I could with the knee injury.”

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