Young speedster Juan Samuel looks like NL's top rookie of 1984

The best rookie in the National League this season is probably 23-year-old Juan Samuel (pronounced sam-well) of Philadelphia. In fact, the Phillies have been monitoring the Dominican-born second baseman's progress so closely in their farm system since 1980 they even knew what he was having for breakfast!

The front office liked what it saw, too. So when it came time to decide whether to keep All-Star infielders Manny Trillo and later Joe Morgan, who had eight Gold Gloves between them, there was no hesitation. The club calmly traded Trillo to Cleveland after the 1982 season, picked up Morgan for one year and then let him go last fall - handing the job to a kid who had played in only 18 big league games.

A gamble? Not if you look at the current National League statistics, which show Samuel leading the league or high up among the leaders in runs scored, hits , triples, and stolen bases.

''With most rookies, there is almost always an element of doubt in some area, '' explained Manager Paul Owens. ''But the way this kid got to balls in the field and stayed aggressive at the plate, you knew he had the stuff to make it. We didn't feel we were gambling at all by making him our second baseman - just giving up a little time until he got the feel of things.

''One thing I wanted him to know was that we were going to stay with him no matter what happened,'' Owens continued. ''So the night before our road opener against Atlanta, I called him into my office for a talk. What I told Juan was that I didn't want him to worry about any errors he might make in the field and not to be disappointed if he didn't hit big league pitching right away. I also told him I knew that eventually everything would come together for him.''

Owens, because he liked Samuel's aggressiveness at the plate and because Juan had stolen 195 bases in four years in the minors, installed the rookie in the leadoff spot in the Phillies' batting order.

''I think the fact that Samuel knew the job was his may have helped him relax ,'' Owens said. ''Anyway, he gave us the speed and the on-base percentage that we wanted right away. Frankly, we were a little amazed when he was safe 11 of the first 12 times he tried to steal.

''Now I don't mean that we are satisfied with Juan completely,'' Owens continued. ''We'd like to tailor that free swing of his to the point where he is more a contact hitter. We'd also like to improve his conception of the strike zone so that he can get the walks that should come naturally to a leadoff hitter. But what we're pushing for is a gradual change and not an overnight one.''

While Samuel has all the physical tools to be a superstar in the field - meaning speed, range, soft hands, and a quick release - he had a little trouble with ground balls early on until Owens discovered what was wrong.

''What was happening was that Juan was rushing everything, getting his feet tangled up, and making errors on balls that he should have handled easily,'' Paul said. ''But once we slowed him down and convinced him he didn't have to throw out every runner by 30 feet, he became much more consistent in the field.

''To me, he's one smart kid,'' Owens continued. ''For example, I know for a fact that he taught himself to speak English and I don't mean just enough to get by, but so well that a lot of people just assume that he was born in the States. I'm not predicting anything for him this year, except that he will steal somewhere between 50 and 60 bases.''

Samuel, 5 ft. 11 in., and 165 pounds and with a younger brother in the Toronto Blue Jays' organization, does interviews with all the assurance of a veteran. Asked what has been his toughest single adjustment as a rookie, Juan replied:

''So far I haven't had to deal with anything I couldn't handle. Most pitchers try to get me out by moving the ball around, but I also saw a lot of that strategy in the minors. I am not a contact hitter. I go up to the plate to swing , not to walk, and I'm not sure if I can or want to change.

''Since I don't know the habits of opposing hitters yet, the Phillies give me hand signals from the dugout until I'm positioned correctly in the field. I've also gotten a lot of tips on how to play certain hitters from (shortstop) Ivan DeJesus. But once I've been around the league a couple of times, I'm sure I'll be able to make these adjustments myself.''

What Owens sees a few years down the road is a young man who will continue to get stronger and smarter until he eventually becomes the Phillies' No. 3 hitter.

''At some point I'm sure Juan will begin to average 20 homers and 90 to 100 RBIs a season,'' Paul said. ''In the meantime we're going to keep him in the leadoff spot and let his progress unfold naturally. Every time I see that aggressiveness of his at the plate, I'm just glad that we've got him instead of somebody else.''