Veteran right-hander Scott Mathieson left Japan on Monday to have surgery on his left knee that will end his season, the Yomiuri Giants announced.
"I feel awful that I'm missing the rest of the season," the 34-year-old right-hander said in a post on his Twitter account. "I will do my best and be ready for spring camp 2019."
Mathieson is in his seventh year with Yomiuri and was named one of the team's captains prior to the season. He has eight saves and 14 holds, a 0-3 record and a 2.97 ERA in 34 games this season.