Hasegawa was drafted in the first round by the
Orix BlueWave in . He won 12 games in his rookie year, and received the
Japanese Rookie of the Year Award in . He was a teammate of
Ichiro Suzuki in Japan and won two championships with the Orix BlueWave. In six seasons with the BlueWave, he was 57–45 with a 3.33 ERA. Hasegawa was purchased by the
Anaheim Angels in January 1997, and he pitched well as a setup man. He signed with the Seattle Mariners on January 14, 2002. In , Hasegawa was named to the American League All-Star team as a middle reliever. He converted 16 of 17
saves at the end of the season when Mariners
closer Kazuhiro Sasaki was injured. He concluded the season with a 1.48
ERA in 63 relief appearances. Hasegawa was not offered a contract by the Mariners after the 2005 season, On January 23, 2006, he announced his retirement despite receiving several offers from MLB and Japanese league teams. In his nine-season MLB career, Hasegawa compiled a 45–44 record with 33 saves and a 3.71 ERA in 517
games. He holds the record for most appearances by an Asian pitcher in Major League Baseball ahead of
Hideo Nomo. Hasegawa was known for releasing the ball very quickly, throwing off the batter's timing. He was very durable, spending time on the
disabled list only once in nine years in the majors. ==Personal life==