A day after failing to win a start for the first time this season, Tokyo Yakult Swallows pitcher Hirofumi Yamanaka was deactivated with a muscle strain on Wednesday.
The 29-year-old submarine right-hander strained his right pectoral muscle in Tuesday's start against the BayStars in Yokohama. Yamanaka, who entered the game a perfect 6-0 in six starts this season, felt discomfort in the third inning. He left the mound after 6⅓ innings, having allowed one run on eight hits and two hit batsmen. He did not figure in the decision, a 3-1 loss.
Yamanaka's condition will be observed after he refrains from throwing for four or five days, but Swallows manager Mitsuru Manaka guessed his surprise package would be sidelined for several weeks.
"One would think it will take around a month," Manaka told reporters at Yokohama Stadium. "We are going to need to consider whether to add a starter or shorten the rotation."
Shortening the rotation may not be an option with veteran Shohei Tateyama only having just returned from his third Tommy John surgery. The Swallows entered Wednesday's games third in the Central League, 3½-games back of the league-leading Hanshin Tigers.
Yamanaka was the least-known player in a four-player deal in July 2014 that essentially sent veteran infielder Keizo Kawashima to the Fukuoka SoftBank Hawks in exchange for former rotation anchor Nagisa Arakaki. Yamanaka came to Yakult having pitched just 32-⅓ innings for the Hawks' first team.
This season, Yamanaka has posted a 2.18 earned run average in 45-⅓ innings.