Yomiuri Giants pitcher and former major leaguer Koji Uehara, who won the World Series with the Boston Red Sox in 2013, announced Monday that his career is over.

"I want to end my 21-year baseball career today," Uehara, told a press conference in Tokyo. "There is a part of me that wants to play on, but I decided from the beginning (of the season) that this is my last."

The 44-year-old right-hander, who made his professional debut with the Giants in 1999 and rejoined the team in March last year, said he has been unable to put in solid performances this season.