Orix Buffaloes ace Chihiro Kaneko will be deactivated after discomfort in his right shoulder caused him to leave Tuesday's game against the Tohoku Rakuten Golden Eagles in the fourth inning.
"Up until that point, I'd felt something but I'd been able to throw," said Kaneko, who had a procedure to clean out the joint in November that delayed his season debut. "But in that inning I thought it was better to stop."
Kaneko had felt some stiffness in his previous start on Aug. 25.
"I'm always extremely cautious regarding my shoulder and have taken care of it," said Kaneko, who last year won both the Sawamura Award as Japan's most exemplary starting pitcher and the Pacific League's MVP Award.
After missing out on the PL pennant last season by the tiniest of margins, the Buffaloes are now mired in last place and have lost their last five games.
"This hurts," interim manager Junichi Fukura said.