WIMBLEDON, England — Yanking off a sneaker with pink accents and purple laces, Serena Williams revealed the scar that starts atop her right foot and meanders up her leg.

It’s a jagged, several-inch remnant — and always-there reminder — of two operations to repair the damage Williams did when cut by glass while leaving a German restaurant last July, just days after winning Wimbledon. That was the first in a series of health scares that wound up sidelining her for about 11 months.

“To this day, I don’t know” exactly how the injury happened, Williams said Sunday, on the eve of this year’s tournament at the All England Club. “Something must have fallen.”

“It’s, like, the biggest mystery next to the Loch Ness Monster. I’ve never been able to figure it out,” she added. “I just remember standing up the whole time, thinking, ‘Ohhhhh, that really hurts.”‘

A request to see the scar came at the end of a question-and-answer session with a small group of reporters, and Williams hardly hesitated. After showing her right foot, she pulled off her other shoe and pointed to a smaller scar on the inside of her left foot, which also was sliced at the restaurant.

“I was, like, ‘Be careful. There’s glass, there’s glass. Be careful,”‘ she recounted. “I’m, like, protecting everyone else. And then I looked down and, like, literally, there’s this massive puddle of blood.”

She wound up playing in an exhibition match against Kim Clijsters in Belgium later that week. But Williams had trouble with her right big toe and eventually had surgery twice on that foot, which she protected for 10 weeks with a cast, followed by 10 weeks in a walking boot. Then, early this year, she was treated for blood clots in her lungs and began taking blood thinners.

At the end of February, she returned to the hospital for another procedure, which she called the “low point” — removing a hematoma, a large gathering of blood under the skin on her stomach.

It wasn’t until about a month ago that she was able to start practicing at full force, and she’s only played two matches heading into Wimbledon, not exactly ideal preparation as the grass-court Grand Slam gets started Monday.

But she is relieved simply to be back.

“I thought, ‘I don’t even know if I’ll be able to play again.’ And then there was a time where it was like, ‘Tennis doesn’t even matter; I just want to get healthy,”‘ Williams said. “Then came a point where I thought, ‘OK, I can definitely play again. I just have to have patience.”‘

She’s scheduled to face 61st-ranked Aravane Rezai of France on Tuesday in what will be Williams’ first Grand Slam match in 50 weeks. Among those on Monday’s schedule: Williams’ older sister, five-time Wimbledon champion Venus; defending champion Rafael Nadal; three-time major runner-up Andy Murray.