ROME - Trying not to make the same mistake as last year and let an injury affect her chances at Roland Garros, top-ranked Serena Williams withdrew from the Italian Open on Thursday with a right elbow problem.

Williams, the defending champion, made the announcement before she was scheduled to face American qualifier Christina McHale in the third round.

"We have to make the right decisions for the future, not for now," Williams said. "You know I hate, hate quitting, and this isn't quitting, it's just making a good decision.

"I was really injured last year, actually, and ended up taking like five days off before Paris and practicing just a day or two before the tournament started," Williams added. "And entering a Grand Slam, you never want to enter it like that, especially as defending champion."

The Italian Open is the last major warm-up tournament for the French Open, which starts in 10 days.

Williams said the injury first affected her at last week's Madrid Open, where she lost to Petra Kvitova in the semifinals.

"I wasn't serving my best or my hardest," she said. "I just have to be able to have a serve and be able to hit my shots with a lot of confidence. When you're injured you don't have as much confidence."

In her Rome opener on Tuesday, Williams beat 39th-ranked Anastasia Pavlyuchenkova 6-1, 6-3.

Williams does not think the injury will affect her at Roland Garros, where she was beaten by Garbine Muguruza in the second round last year.

"I don't think it will. I think if I continue to play it could get worse and then I could have a situation on my hands," Williams said. "I've learned from some things in the past. If I continue to play it could not only hurt my chances for Roland Garros but maybe for Wimbledon.

"I think it was a mature decision for me," she added. "I've made some bad decisions in the past."