Venus Williams says qualifying for the Olympics is her primary goal this season. (Michel Spingler/AP)

Eyeing a potential conflict with the London Olympics, the Washington Kastles have moved up this summer’s appearance by marquee player Venus Williams.

Williams will join the defending World TeamTennis champions for their July 16 match against the Boston Lobsters at Kastles Stadium on the Wharf.

She was scheduled to compete on July 24. But her commitment was moved up to avoid a conflict if Williams qualifies for the 2012 London Games. The tennis competition, to be held at Wimbledon’s All England club, runs July 28-Aug. 5.

The Kastles will honor all tickets purchased for her July 24 appearance on the rescheduled date or offer refunds, if fans prefer.

Williams, 31, who has won three Olympic gold medals (the 2000 Sydney singles and doubles titles, with younger sister Serena; and the 2008 Beijing doubles gold, also with Serena), revealed last fall that she had received a diagnosis of an autoimmune disorder, Sjogren’s Syndrome, that can cause fatigue and joint pain. Competing in her first Grand Slam tournament since withdrawing from the 2011 U.S. Open, she reached the second round of the French Open last week.

A five-time Wimbledon champion, Williams told reporters on the eve of the French Open that qualifying for the Olympics was her primary goal this season.

In order to qualify for the Olympics, players must be ranked among the top 56 in the world as of June 11. In addition, countries are limited to four men and four women.

Venus is currently the third-highest ranked American woman (53rd), behind Serena (No. 5) and Christina McHale (No. 36). Compatriots Varvara Lepchenko and Sloane Stephens, ranked 63rd and 70th, respectively, advanced to the French Open’s fourth round and, as a result, are expected to move higher when the rankings are re-tabulated June 11. But neither is expected to overtake her in the rankings.

This summer’s Olympic competition marks the return of mixed doubles as a medal event for the first time since 1924.

Last season the Williams sisters helped the Kastles to the first perfect season in World TeamTennis history and a second league championship.

The Kastles open their home season July 12 against the New York Sportimes, led by former No. 1 Martina Hingis. Serena Williams’s scheduled home appearance for the Kastles is July 22 against Kansas City.

The Kastles’ six-match home season ends July 24 against Philadelphia.