Fish, 30, underwent a procedure on May 23 for heart palpitations. He is set to play home matches for the Sacramento Capitals of World TeamTennis on July 12 and 13.
Fish achieved his best result at Wimbledon last year by reaching the quarterfinals, losing to Rafael Nadal in four sets. Fish next will face British wild card James Ward, who outlasted Pablo Andujar of Spain 4-6, 6-0, 3-6, 6-3, 6-3. Ward, 25, is ranked No. 173.
Also advancing was Sam Querrey, a 6-foot-6 native of San Francisco who's scheduled to play five matches for the Capitals later in the July season. Querrey topped Vasek Pospisil of Canada 7-5, 6-7 (5), 6-3, 6-4 to earn a likely meeting with another Canadian, 21st-seeded Milos Raonic, in the second round.
Raonic, the two-time reigning SAP Open champion in San Jose, leads Colombia's Santiago Giraldo, who won the 2009 Sacramento Challenger, 6-4, 6-4, 5-4 in a match suspended by darkness.
The Capitals' Kevin Anderson, seeded 32nd, lost to promising Grigor Dimitrov of Bulgaria 7-5, 7-6 (30, 6-7 (4), 6-3. Anderson, a 6-foot-8 South African, is set to play the last three matches of the regular season for Sacramento.
CoCo Vandeweghe, another part-time Capital, trails 10th-seeded Sara Errani of Italy 6-1, 5-3 in a first-round match halted by fading light. Errani reached the final of the recent French Open, falling to Maria Sharapova.
Olympic entries announced -- Bob and Mike Bryan will try to fill the only remaining gap on their resume and Dmitry Tursunov will hope for a better draw when they compete in the Olympic tennis event July 28-Aug. 5 at Wimbledon.
The Bryan twins, who won the 1998 NCAA doubles title as Stanford sophomores, will represent the United States. Tursunov, a Moscow native and longtime Sacramento-area resident, will play for Russia.
The International Tennis Federation on Tuesday announced entries for the men's and women's 64-player singles draws and 32-team doubles fields. Direct acceptances were based on the world rankings of June 11, with a limit of four singles players per gender per country. Nations also could nominate up to two doubles teams per event, with a maximum of six players per gender per country total.
Entries for mixed doubles, which will return to the Olympics for the first time since 1924, will be determined on site from players already participating in singles or doubles.
The Bryans have won all four Grand Slam men's doubles titles at least once, and they played on the United States' 2007 Davis Cup championship team. But their best Olympic result is a bronze medal in 2008, when they lost to eventual champions Switzerland's Roger Federer and Stanislas Wawrinka in the semifinals at Beijing.
At 34, the Bryans likely have two remaining chances, this year and in 2016 in Rio de Janeiro, to earn gold.
Tursunov lost to Federer not once but twice in Beijing, falling 6-4, 6-2 in the first round of singles and 6-4, 6-3 with Mikhail Youzhny to Federer and Wawrinka 6-4, 6-3 in the secound round of doubles.
Notable absences from the London entries are Fish and former Capital Vania King.
Fish, ranked second in singles among U.S. men at No. 12, was eligible but chose to skip the Olympics for the second straight time. He remains emotionally scarred after failing to capitalize on a two-sets-to-one lead over Nicolas Massu of Chile in the gold-medal match at the 2004 Olympics in Athens.
“I had some great memories from Athens," Fish told the New York Times, "and if you would have told me before the tournament that I’d get a medal, I would have taken it 100 percent and probably would have thought you were lying. But then being put in that scenario and two sets to one up in a match I really I was going to win. I mean I was going to win the whole thing, and even just thinking about it is really hard.”
King, currently ranked 61st in singles, fell just short in that event. She is ranked ninth in doubles, but the U.S. bids went to top-ranked Liezel Huber and Lisa Raymond and two-time Olympic gold medalists Venus and Serena Williams. Huber (South Africa) is a naturalized U.S. citizen, as is singles entrant Varvara Lepchenko (Uzbekistan).
Friday -- Early rounds, ESPN, 4 a.m.-2 p.m. (live). Wimbledon Primetime, Tennis Channel, 2 p.m. (premiere), 6 p.m. (repeat), 10 p.m. (repeat).
Saturday -- Early rounds, 5 a.m.-noon, ESPN (live). Wimbledon Primetime, Tennis Channel, 2 p.m. (premiere), 6 p.m. (repeat), 10 p.m. (repeat).
Sunday -- No matches scheduled. Wimbledon Primetime (first-week highlights), Tennis Channel, 1 p.m. (premiere), 5 p.m. (repeat), 9 p.m. (repeat).
Monday -- Fourth round, Courts 1 & 2 and outer courts, ESPN2, 4 a.m.-2 p.m. (live), Centre Court, ESPN, 5 a.m.-noon (live). Wimbledon Primetime, Tennis Channel, 2 p.m. (premiere), 6 p.m. (repeat), 10 p.m. (repeat).
Tuesday, July 3 -- Women's quarterfinals, Courts 1 & 2, ESPN2, 4 a.m.-1 p.m. (live), Centre Court, ESPN, 5-10 a.m. (live). Wimbledon Primetime, Tennis Channel, 2 p.m. (premiere), 6 p.m. (repeat), 10 p.m. (repeat).
Wednesday, July 4 -- Men's quarterfinals, Courts 1 & 2, ESPN2, 4 a.m.-1 p.m. (live), Center Court, ESPN, 5 a.m.-noon (live). Wimbledon Primetime, Tennis Channel, 2 p.m. (premiere), 6 p.m. (repeat), 10 p.m. (repeat).
Thursday, July 5 -- Women's semifinals, ESPN, 5-10 a.m. (live). Wimbledon Primetime, Tennis Channel, 2 p.m. (premiere), 6 p.m. (repeat), 10 p.m. (repeat).
Friday, July 6 -- Men's semifinals, ESPN, 5-11 a.m. (live). Wimbledon Primetime, Tennis Channel, 2 p.m. (premiere), 6 p.m. (repeat), 10 p.m. (repeat).
Saturday, July 7 -- Women's final, ESPN, 6-11 a.m. (live), ABC, noon-3 p.m. (repeat), Wimbledon Primetime, Tennis Channel, 4 p.m. (premiere), 8 p.m. (repeat), midnight (repeat).
Sunday, July 8 -- Men's final, ESPN, 6 a.m.-noon (live), ABC, noon-3 p.m. (repeat). Wimbledon Primetime, Tennis Channel, 4 p.m. (premiere), 8 p.m. (repeat), midnight (repeat).
Friday -- Renowned tennis psychologist and author Allen Fox speaks at 5:30 p.m. at the Gorin Tennis Academy, 8970 Carriage Drive, Granite Bay (Sacramento area), $10, (916) 797-8444.
July 7-10 -- West Coast Junior Championships, Rio Del Oro Racquet Club, 119 Scripps Dr., Sacramento, www.norcal.usta.com.
July 7-15 -- WTA, Bank of the West Classic, Stanford University, www.bankofthewestclassic.com.
July 9 -- World TeamTennis, Sacramento Capitals' season opener at Boston, 4 p.m., www.saccaps.com.
July 12 -- World TeamTennis, Capitals' home opener (with Mardy Fish) vs. Kansas City, Sunrise Marketplace Stadium, Sunrise Mall in Citrus Heights, 7:35 p.m., www.saccaps.com.
July 12 -- 2012 Northern California Tennis Hall of Fame Brunch and Induction Ceremony (Nick Saviano, Andrea Norman, Steve Cornell and Martha Downing), Stanford University, Pac 12 Plaza/Cardinal Plaza, 10:30 a.m.-1:30 p.m., tickets $75 each at http://www.acteva.com/booking.cfm?bevaid=230538.
July 28-Aug. 5 -- OLYMPIC TENNIS TOURNAMENT at Wimbledon, www.london2012.com.