That trio joined 18th-seeded John Isner, 21st-seeded Sam Querrey, Ryan Harrison, Steve Johnson, Alex Kuznetsov, Wayne Odesnik, Rajeev Ram and Michael Russell on the way home.
"It's a tough stat to hear, but I still believe, right now, where U.S. tennis is, not too many guys are in their prime. That's why the numbers are like that. But a lot of guys are, maybe, in the tail end of their careers and a lot of guys are coming up," said Kudla, a 20-year-old from Arlington, Va., who is ranked 105th. "Maybe next year, or the year after that, things could change. You have to go through a little bit of a struggle to get some success."
Led by top-seeded and defending champion Serena Williams, the U.S. women still are represented in singles at Wimbledon this year.
Williams extended her winning streak to 33 matches, the longest on tour since 2000, by eliminating 100th-ranked qualifier Caroline Garcia of France 6-3, 6-2, while 18-year-old Madison Keys knocked off 30th-seeded Mona Barthel of Germany 6-4, 6-2.
Keys next plays 2012 runner-up Agnieszka Radwanska of Poland, and Williams goes from a 19-year-old opponent in Garcia to a 42-year-old opponent in Kimiko Date-Krumm, the oldest woman to reach the third round at Wimbledon since the Open era began in 1968.
"I have so much respect for her. I think she's so inspiring to be playing such high-level tennis at her age," said Williams, who at 31 is the oldest No. 1 in WTA rankings history.
Already into the third round with a victory a day earlier was No. 17 Sloane Stephens, while yet another American, wild-card entry Alison Riske, had her match against Urszula Radwanska Agnieszka's younger sister postponed by rain Thursday.
"I can't put my finger on why the women are doing better than the men," Reynolds said.
He wound up facing Djokovic with Centre Court's retractable roof closed because of the first drizzles of the fortnight, which prevented five singles matches from starting and forced the suspensions of three others in progress.