Querrey, U.S. lead Serbia 2-0 in Davis Cup opener

   A trip to Serbia normally spells trouble for the United States Davis Cup team.
   But with Serbia missing its top three players, towering Sam Querrey and John Isner gave the United States a 2-0 lead today on indoor clay in Nis in the first round.
   It still wasn't easy, especially without the No. 1 American.
   Sam Querrey, a 6-foot-6 (1.98-meter) San Francisco native, pounded 20 aces in a 6-7 (4), 6-2, 7-5, 6-4 victory over 88th-ranked Laslo Djere in the opening match. Isner, 6-foot-10 (2.08 meters), blasted 24 aces in a 6-4, 6-7 (6), 6-3, 3-6, 7-6 (4) win over 84th-ranked Dusan Lajovic.
   Absent are No. 13-ranked Novak Djokovic, No. 38 Filip Krajinovic and No. 67 Viktor Troicki for Serbia and No. 8 Jack Sock for the United States. Djokovic, formerly ranked No. 1, announced today that he had a "small medical intervention" on his right elbow.
   Querrey is ranked a career-high 12th, and Isner is 18th.
   The United States can clinch the best-of-five series in Saturday's doubles match, in which Ryan Harrison and Steve Johnson will face Nikola Milojevic and Miljan Zekic. Harrison won the French Open last year with Michael Venus of New Zealand.