Novak Djokovic wins but can’t shake troubles

Novak Djokovic double-faulted, shook his right arm and grimaced. Seconds later Monday night, a weak serve produced a wince, then was followed by a missed forehand that gave away a set in the defending champion’s first-round U.S. Open match.

While he managed to finish a 6-3, 5-7, 6-2, 6-1 victory over Jerzy Janowicz of Poland, there were signs of trouble, starting with a visit from a trainer who massaged Djokovic’s arm after only five games.

Asked about his health during an on-court interview, Djokovic deflected the question, saying, “I don’t think it’s necessary to talk about this now. I’m through. I’m taking it day by day.”

During the match, the winner of 12 Grand Slam titles hit first serves around 100 mph, 25 mph or so below his norm, and second serves in the low 80s. And he repeatedly flexed that right arm.

This was the No. 1-ranked Djokovic’s first match at a major tournament since losing to Sam Querrey in the third round of Wimbledon, which ended the Serb’s bid for a calendar-year Grand Slam after he won the Aus- tralian and French opens.

Heading into the U.S. Open, Djokovic spoke about a left wrist injury that flared up before the Rio Olympics, where he lost in the first round. But that didn’t appear to bother him Monday.

Earlier on Day One, another two-time Open champion, Rafael Nadal, won his first Grand Slam match in three months, 6-1, 6-4, 6-2 against Denis Istomin; 20th-seeded John Isner’s rallied from two sets down to edge 18-year-old U.S. countryman Frances Tiafoe; 26th-seeded Jack Sock pulled out a five-set victory over 18-year-old Taylor Fritz in another all-American matchup; and Rio women’s gold medalist Monica Puig of Puerto Rico fell to Zheng Saisai of China.