Giants right-hander Shun Yamaguchi was suspended for the remainder of the season on Friday after charges against the 30-year-old were referred to prosecutors over an incident last month.
The pitcher, who joined the Tokyo team in the offseason after filing for free agency with Central League rival DeNA BayStars, is accused of causing bodily harm and property damage at a hospital in the Japanese capital's Meguro ward.
According to police and other sources, Yamaguchi had been out drinking and visited the hospital early on the morning of July 11 to have an injury to his pitching hand treated.
He is accused of shoving a male security guard in the chest, causing him to crash into a desk, leaving bruising on his lower back that lasted for two weeks. He also reportedly damaged a door at the hospital.
"I am truly sorry for having caused such a situation through my bad behavior," Yamaguchi told a press conference at the team's offices in Tokyo.
According to the ballclub, a settlement has been reached with parties involved and a claim for damages has been withdrawn.
Yamaguchi, whose father fought in sumo's upper-echelon makuuchi division, turned pro after being drafted by the BayStars in the first round of the 2005 high school draft.
The Yokohama club's closer from 2009 to 2012, Yamaguchi was successfully converted to a starter in 2014, and left the BayStars after last season to join the Giants on a three-year deal.
His tenure with the Giants, however, got off to a slow start. Due to discomfort in his right shoulder, he did not make his first-team debut until June. He is 1-1 with a 6.43 ERA in four starts.
Yamaguchi allowed 12 runs over nine innings in his starts on July 2 and July 9. He was scheduled to start against the Chunichi Dragons on July 18, but was a late scratch when news of the incident broke.