Madison Keys says that a left wrist problem was the reason she withdrew from the Rogers Cup in Toronto. The world No. 19 lost to Ajla Tomljanovic in the second round in Stanford and decided not to play in Toronto because she wanted to make sure that she could play Cincinnati, New Haven, and the U.S. Open.

The 20-year-old said that she is learning to pay attention to when she is legitimately hurt and should pull out of tournaments.

"It's always tough," said Keys at Cincinnati, where she lost her second-round match to Jelena Jankovic, 7-6 (4), 6-4. "It's never an easy thing to pull out of a tournament. You always want to play. But I think there has been so many cases where I've gotten hurt at a Grand Slam. Pulling out of Wimbledon [in 2014] because I was hurt was the worst thing. For me, learning from experience and not pushing myself to the point of completely breaking down is the smarter choice."  
This season, Keys has reached the semifinals at the Australian Open and the quarterfinals at Wimbledon. She also reached the final in Charleston, but she lost early in Indian Wells, Miami, and the French Open.  
"I think my movement has gotten a lot better," Keys said. "I've been working on it a lot. I think it hasn't shown a ton, but at the same time, I've been having less of the bad matches where I came off the court and I was really disappointed with how I competed."