Kazuhiro Sasaki
Saito played for Tohoku Fukushi University in Sendai during his college years alongside players such as former Seattle Mariners closer Kazuhiro Sasaki and former player and current Hanshin Tigers manager Tomoaki Kanemoto. Saito was originally a position player, but he became a pitcher in his second year in college. He was drafted in the first round by the Yokohama Taiyo Whales in . He was an All-Star a total of four times while in Japan (, , , ), and he led the Central League in strikeouts with 206 in 1996. He was found to have a dislocated cartilage in his right elbow in the spring of and had to undergo surgery, and he spent the rest of the season rehabbing. He returned in , winning 13 games while posting a 2.94 ERA. His team, the BayStars, also won the Japanese championship series for the second time in 38 years. He became the team's closer after incumbent Kazuhiro Sasaki left the BayStars to join the Mariners in . His record was 7–1 with 27 saves with a 1.67 ERA in 2001. Saito returned to his starting role in but did not win more than 6 games in a season between 2003 and .