The Yakult Swallows, now in the Central League playoffs, said Monday the number of their players tested positive for influenza A has grown to five from three a day earlier.
Ryohei Kawamoto, who hit a two-run homer in Sunday's 3-2 loss to the Chunichi Dragons in Game 2 of the Climax Series first stage, and fellow catcher Atsushi Kinugawa are the latest ones infected with the flu.
Kawamoto complained of fever after Game 2 and Kinugawa during the game.
Yakult is playing a decisive Game 3 on Monday night for a spot against the Yomiuri Giants in the second stage of Climax Series.
On Sunday, the team said right-handers Yuki Tanaka and Hiromitsu Takagi, who were both on standby as starters, and utility infielder Yoshiyuki Noguchi have tested positive for influenza A.