Two Yomiuri Giants players have tested positive for the new coronavirus, the Central League team announced Wednesday, casting a shadow over Nippon Professional Baseball’s plan to start the 2020 season on June 19.

Giants shortstop Hayato Sakamoto and catcher Takumi Oshiro are the first pro baseball players in Japan known to have tested positive for the pneumonia-causing virus since Hanshin Tigers pitcher Shintaro Fujinami and two teammates were infected in late March.

In order to limit the further spread of the virus, the Giants canceled Wednesday’s practice game against the Seibu Lions.

NPB started playing practice games Tuesday after settling on a June 19 start to the season. A 143-game campaign that was due to begin on March 20 has been shortened to 120 games due to the delay. The contests were going to be held behind closed door initially.

The Nippon Professional Baseball season, which has been delayed by the coronavirus pandemic, will begin June 19, the league announced on Monday.

The decision comes after the government’s advisory panel approved the plan to end Japan’s nationwide state of emergency for the five prefectures still under the order, including Tokyo and Hokkaido, earlier in the day.

The 2020 campaign will begin without fans in attendance, though the league will continue to monitor the situation in hopes of allowing spectators into ballparks later in the summer.

Opening day was originally scheduled for March 20 before being postponed because of the COVID-19 outbreak.