Nippon Professional Baseball said Monday it plans to test all of its players and coaches for the new coronavirus once a month after the season opens on June 19.

At an online meeting with representatives of the 12 teams, NPB also decided to conduct polymerase chain reaction tests before the season for players, coaches and umpires.

The decision was made following a recommendation by a panel of infectious disease experts that has been meeting with executives of NPB and the J-League, the country's pro soccer body. The panel said NPB should test players using their saliva every month.

The J-League, which suspended play in February, has already decided to test all of its players every two weeks. The first division is set to resume on July 4.

The experts also presented a proposal for when players who test positive for the virus can join their teams. It said those who did not show symptoms can return after testing negative twice during a period to observe their health.

On Wednesday, the Yomiuri Giants said two players tested positive for the new coronavirus. NPB, however, said the players' infections would not impact the opening day decision.

The players, shortstop Hayato Sakamoto and catcher Takumi Oshiro, showed no symptoms of the disease and have tested negative twice since the announcement.