BELGRADE—The prospect of winning an Olympic gold medal for Serbia outweighs the disappointment of playing in an empty venue at the Tokyo games, the men’s world tennis number one Novak Djokovic said on Monday. Djokovic considered pulling out of the Olympics due to COVID-19-related restrictions after winning Wimbledon this month but decided to head to Japan for what he called patriotic reasons. Brimming with confidence in a televised interview with Montenegro’s MINA news agency in the coastal republic’s resort of Herceg Novi, Djokovic said Croatia’s former Olympian Blanka Vlasic had helped persuade him not to pull out. “It came down to patriotism and my feelings for Serbia,” Djokovic said after completing a practice session on a hardcourt surface. “I am not overjoyed about playing with no fans present or about the various coronavirus restrictions effective in Japan, but representing your country in the Olympics is indispensable. “I came across Blanka …