Kanazaki's positive test comes less than a week after the J.League announced plans to restart the campaign on July 4, albeit without fans in stadiums, and as many clubs returned to full training.
Each team had played only one league match when the campaign was suspended on Feb. 26.
The club said Kanazaki, who has 11 caps for Japan, reported a temperature of 38.5 Celsius after training on Friday and received the result of his coronavirus test on Tuesday.
With restrictions eased across Japan, professional sports teams, including Nippon Professional Baseball clubs, have been returning to training.
Japan has been largely successful in containing COVID-19, recording 17,000 infections and 914 deaths. (Reporting by Jack Tarrant; Editing by Peter Rutherford )
Chris Froome (Stage 20, 2015)
Day 10, Round 5