Los Angeles — One of the surest ways to remain competitive in major league baseball is not to let your roster become overloaded with veteran players, especially if you've got a farm system that regularly produces first-rate replacements. That was the idea of General Manager Al Campanis of the Los Angeles Dodgers last winter when the club didn't re-sign free agent Steve Garvey and traded third baseman Ron Cey to the Chicago Cubs.
What Campanis did was open up two spots in the lineup for solid-hitting rookies Greg Brock, who slugged 44 home runs last year with Albuquerque, and Mike Marshall, the 1981 Minor League Player of the Year.
Even though first base is the best position for both players, Brock was picked to replace Garvey because he lacks the speed desired to play elsewhere. Meanwhile, Dodger coaches devoted hours in spring training to teaching Marshall how to play right field. Of course that meant shifting Pedro Guerrero from the outfield to third base, which was not all that big a gamble since Guerrero started his career as an infielder.
With Los Angeles having begun the season well, almost immediately rising to the top of the National League West and staying there, there has been a tendency to give much of the credit to Brock and Marshall.
Brock, a left-hander who arrived with the reputation of being able to hit left-handed pitching, jumped out quickly, swinging for both average and power. One night he hit two home runs (one a grand slam) and drove in six runs. But since then he has gone through a 2-for-32 stretch.
Marshall, who was a lot less selective at the plate than Brock to begin with, was also doing well early until he was temporarily sidelined by a fastball that removed his batting helmet and knocked him down. Since then he has had one of the biggest strike zones in the league, regularly swinging at balls in the dirt and way outside. Result: Mike's average has plummeted. He is currently out of the lineup and on the team's 15-day disabled list.
Asked for an update on Brock and Marshall, Campanis replied: ''You have to be patient with kids, especially those that you entrust with a big responsibility, because nobody learns it all right away. It took Garvey almost three years before he began to hit the way we thought he could, and these kids deserve the same chance. Between them they have already driven in quite a few runs. And to me that's a lot better than a high batting average.''
To set the record straight, the key to the Dodgers' success so far has been a pitching staff with one of the lowest earned-run averages in either league, plus a bullpen that has exceeded everyone's expectations. However, the bullpen lost its stopper this week when Steve Howe, who hadn't allowed an earned run all season, was lost to the club indefinitely while he deals with personal problems.
Meanwhile the Dodgers, who have produced the last four National League Rookies of the Year in Rick Sutcliffe, Howe, Fernando Valenzuela, and Steve Sax, can't necessarily count on either Brock or Marshall being No. 5. Instead that honor could go to LA right-hander Alejandro Pena (5-1), who has been a great spot starter after previously showing little aptitude as a relief pitcher. Three seasons in one
From manager Chuck Tanner of the Pittsburgh Pirates: ''In my opinion, the way to look at any pennant race is to divide it into three 54-game seasons; with the second series of 54 games the most important. Because of weather postponements, you almost never need more than a four-man pitching rotation in your first 54 games; your bullpen is still fresh; and the injuries that clubs have to deal with haven't yet begun to take their toll.
''But during those second 54 games, you're often forced to rely on your No. 5 and 6 pitchers; your bullpen becomes overworked; and you begin to have to go to your bench. If you can continue to win while that is happening, then you've got a contender. But if your club falls apart during that period, then your final 54 games aren't going to mean much anyway.'' Tidbits from around the majors
* Outfielder Dan Ford of the Orioles was about as popular in Baltimore last year as an order of crab cakes left in the oven too long. A lot more was expected of Ford than a .235 batting average and only 43 RBIs. But Dan made headlines recently by hitting a home run in three consecutive games and collecting three game-winning hits. He later admitted to reporters that he had made an adjustment in his stance. ''I'm not turned around nearly as much as I was,'' Ford explained. A right-handed hitter, he used to point his left shoulder down the first base line.
* Although Greg Luzinski of the Chicago White Sox missed tying Frank Howard's American League record of hitting a home run in six consecutive games, he did homer in five straight. The major league mark for hitting home runs in consecutive games belongs to the Pirates' Dale Long, who had an eight-game string in 1956.
* Pittsburgh tied a major league record set by the Chicago White Sox in 1909 when pitchers Jim Bibby and Jim Winn walked seven consecutive Atlanta hitters in the third inning of a 6-0 Braves' victory.