DANIEL ISLAND, S.C. — A year ago, Laura Siegemund was coming off a surprising title in her hometown tournament in Stuttgart, Germany, and was considered a contender for the French Open. Then, abruptly, her hopes and right leg buckled.

At a tournament in Nuremberg, Germany, in May, the week before the French Open, Siegemund fell awkwardly as she slid to her right, tearing her right anterior cruciate ligament. She was carried off court on a stretcher, her season over.

Barbara Rittner, then the German Fed Cup captain, was with Siegemund as she lay on court, and she recounted Siegemund’s words in an interview on German television that day.

“This cannot be true — why now?” Rittner quoted Siegemund as saying.

The shock wore off quickly, replaced by clarity, Siegemund said in a recent interview. She realized she had gained something tennis players almost never have: free time.