Toronto Blue Jays (1977-present)

Seattle Mariners (1977-present)

Player must have played for only one major league franchise, or only one AL/NL team, in their career. For example, Tony Gwynn (only played for one team, an AL/NL team), Buck Leonard (only played for one team, a Negro Leagues team), Jackie Robinson (only played for one team in AL/NL, but additionally played for a team in the Negro Leagues), and Mike Griffin (only played with one team in the AL/NL, but additionally played in the AA and PL) would all qualify.