Righthanded reliever Guillermo Mota says he'd never thrown a pitch in an organized baseball game before the Expos selected him in the Rule 5 minor league draft, in December 1996. At the time he was an infielder in the Mets' system. "On a lot of my throws the first baseman would say, 'Hey, you hurt my hand!' " Mota says. Having proved that he couldn't hit (he had a .241 minor league average), he was asked by Montreal if he would consider pitching. "Everything was totally new," says Mota, who had to be taught how to wind up. As a rookie in '99, he was 2-4 with a 2.93 ERA in 51 games. Armed with a fastball that tops out in the mid-90s, Mota and the Expos expect bigger things in 2000. "He could become a stopper someday," says general manager Jim Beattie. "He challenges hitters. Maybe that comes from his perspective of knowing that it's not easy to hit." Or is it? In Mota's first (and only) at bat in the majors last summer, he hit a three-run homer.