Tetsuya Yamaguchi (山口 鉄也)
- Bats Left, Throws Left
- Height 6' 0", Weight 190 lb.
- High School Yokohama Shogyo High School
- Born November 11, 1983 in Yokohama, Kanagawa Japan
Tetsuya Yamaguchi was a pitcher for the Yomiuri Giants.
After high school, Yamaguchi was signed by the Arizona Diamondbacks. In 2002, he was 1-1 with a 3.94 ERA in 21 games and fanned 39 batters in 32 innings for the Missoula Osprey. He was converted to a starter and posted a 6-7, 4.55 record in 2003, still with Missoula. In a third year with the Osprey, 2004, he fell to 0-5, 6.22 and allowed 81 hits in 55 innings for a .351 opponent average. The Diamondbacks then let him go.
In the 2005 draft, Yamaguchi was picked by the Yomiuri Giants. He had a 1.61 ERA in the Eastern League for them that year. In 2007, the southpaw made his debut in Nippon Pro Baseball, going 2-0 with a 3.91 ERA in 32 games; used as a LOOGY, he only worked 25 1/3 IP.
Yamaguchi excelled as a reliever in 2008. In 67 games and 73 2/3 IP, he allowed only 61 hits and 12 walks while striking out 69. He went 11-2 with two saves and a 2.32 ERA. He tied Takehiko Oshimoto for third in the Central League in appearances, two behind leader Tomoyuki Kubota. He also tied Tsuyoshi Shimoyanagi and Masahiro Yamamoto for 7th in victories and was 7th in save points. He won the 2008 Central League Rookie of the Year Award. Yamaguchi fanned 7 in 4 2/3 scoreless innings in the 2008 Japan Series but Yomiuri lost to the Seibu Lions.
Tetsuya pitched four games for Samurai Japan when they won the 2009 World Baseball Classic, allowing one hit and one walk in 2 shutout innings.
When he pitched in his 71st game of 2009, he broke Brian Sikorski's club record for appearances. He pitched for the club through 2018, announcing his retirement that October. He went 52-27, 2.40 in 660 NPB games and 59-40, 2.93 in 709 games at all levels.