Tennis superstar Serena Williams plans to submit herself to more medical tests after her early exit at the Wimbledon caused by a viral illness.

The 32-year-old athlete told USA Today that she has already learned her lesson at the recent Wimbledon. "Now I know better if I'm feeling bad I'm not going to step on the court," Williams was quoted as saying in the report.

It was observed that Williams appeared weak and not her usual self when she played the second-round doubles with older sister Venus. USA Today notes that prior to her doubles game, Williams also lost to French Alize Cornet during the third round of the singles match.

The same report notes that the viral illness that caused her another championship had also left her bedridden for three days and she was not able to travel.

"I was really, really sick. Especially me, when I lose I'm on the very next flight out of there," she added.

According to USA Today, Williams is scheduled to undergo more tests "for things that do run in the family." It can be remembered that her sister Venus is also suffering from Sjogren's syndrome.

In a similar report by The Star, the tennis player admitted that she was also scare about what was happening to her.

"I didn't realize how I felt until later. In the moment I didn't realize how sick I was. It's weird but that's the fight in me. I never know when to say when," Williams said.

She also told The Star that she could have continued fighting had Venus not insisted that she leave the court. "She kept saying, 'Walk off the court, I'm the older sister and I say you have to leave.'" Williams said. 

Weeks after her devastation at the Wimbledon, Williams is now back to prove one more time that she still got the skills. She is scheduled to go against Czech Republic's Karolina Pliskova on Wednesday night at the Bank of the West Classic.

"I feel really good. I feel really happy to be here," Williams was quoted by USA Today as saying.

She also told The Star that the tournament has always been "a special place for her."

"I've always felt good about this tournament and just being here," Williams said.

The Star notes that Williams used Bank of the West to restart her career in 2011 and where she also recorded her first WTA tile in more than a year.