IT seems like only yesterday that Bob Sheppard was carefully preparing to pronounce Spanish names like Valdivielso and Aparicio and Miñoso. Last night, the august Yankee public-address announcer did his homework with a Japanese source before introducing Ichiro Suzuki as the leadoff hitter for the Seattle Mariners.

Sheppard, who has merely been at this for 50 years, was wearing his satiny Nippon Ham Fighters jacket for the occasion. It had come as a gift during transactions between the Japanese club and the Yankees a few years ago.

''My ceremonial robe,'' Sheppard said.

Baseball has gone international, what with a solid quarter of its players coming from outside the United States. Europeans are prominent in hockey and growing in basketball. The four goals scored so far in the new Women's United Soccer Association have been by a Brazilian, two Germans and an English player.

The latest wave in baseball includes Ichiro, as he is known in all his single-name stardom, a slim and intense right fielder.