The highlight of the Seattle Mariners' 2003 season was having the five-man starting rotation start and finish the season as a group. Right-handers Freddy Garcia, Joel Pineiro, Gil Meche and Ryan Franklin, along with left-hander Jamie Moyer, were the first five-some since the 1966 Dodgers to start all 162 regular-season games. Moyer, who in 2001 became the oldest pitcher in MLB history to reach the 20-win plateau for the first time his career, did it again in '03 and went one better. He finished the season with a 21-7 record and earned his first All-Star Game appearance. Meche landed the AL Comeback Player of the Year Award, becoming the first pitcher since Whitey Ford in 1954 to win at least 15 games after not winning any games the previous two seasons. Second baseman Bret Boone led the team in home runs (35) and RBIs (117). The Seattle Mariners led the AL West (134 days) longer than anyone in the division and won 93 games for the second consecutive season. But they couldn't hold off the Athletics and fell two games short of the AL Wild Card playoff berth.

Ichiro Suzuki made history again in 2004 by breaking a record that lasted 84 years. But, unlike his breakthrough season in 2001, this time his exploits were lonely highlights for the Seattle Mariners. Ichiro passed the single-season record for hits set by George Sisler in 1920 with his 257th and finished with 262 while claiming the American League batting title with a .372 average. The Seattle Mariners as a club struggled, falling swiftly down to the AL West cellar with a 53-99 record. While Ichiro chased the hits record, all-time Seattle Mariners great Edgar Martinez played his last games in a Seattle uniform, capping it all off with a special season-ending weekend in his honor. Following the season, the club dismissed second-year manager Bob Melvin and replaced him with longtime American League skipper Mike Hargrove.