He’s More Than a Spare Part : Baseball: Darrin Jackson becomes the everyday outfielder the Padres doubted he could be.

He’s the other guy.

He is not bidding for the triple crown. His home runs don’t fly into upper decks. It has been nearly five years since he even stepped foot in Tampa, Fla.

Although the Padres’ focus this season has centered on the Tampa connection of Gary Sheffield and Fred McGriff, there’s a man who quietly is having one of the finest seasons of any center fielder in the National League.

His name is Darrin Jay Jackson, and no center fielder in the NL has more than his 14 homers, and only the Pirates’ Andy Van Slyke has more than Jackson’s career-high 57 RBIs.

“It’s funny, I’m having the best year of my career,” Jackson said, “but by comparison to Gary and Freddy, I feel like I’m having a lousy year.

“I guess I should be happy with the numbers I put up, though, because with those two guys batting ahead of me, they don’t leave too much on the bases.”

Indeed, Sheffield and McGriff have combined for 52 home runs and 162 RBIs this season, amassing 473 total bases. There’s not a more prolific 3-4 combination in the major leagues.

But if you ask opposing managers, Jackson is responsible for helping force pitchers to face Sheffield and McGriff.

“People take that guy for granted,” Cincinnati Reds Manager Lou Piniella said, “but he’s a hell of a player. You can’t just tell your pitcher, go walk Sheffield and McGriff and take your chances with Jackson.

“Believe me, that guy can hurt you just as much.”

Jackson’s numbers might pale in comparison to those of Sheffield and McGriff, but there are some revealing facts: The Padres, the league’s top offensive team, have an 11-2 record when Jackson homers; nine of his 14 homers have either won a game, tied a game or given the Padres a lead; and the Padres are 19-4 in the last 23 games in which Jackson has an RBI.

Not bad for a guy whom the Padres spent the winter and spring trying to trade. Jackson was offered in a package for Ellis Burks of the Boston Reds Sox, Sammy Sosa of the Chicago White Sox and even Gary Thurman of the Kansas City Royals.

Although Jackson last season hit .262 with a career-high 21 homers and 49 RBIs--that while not becoming an everyday starter until Aug. 11--the Padres believed it was a fluke. They wanted to deal him while his trade value was high.

It might be the best move the Padres never made.

“Of all of our position players,” said Joe McIlvaine, Padre general manager, “he’s the most the most pleasant surprise for us. Baseball has a way of categorizing players, and many people thought--including us--that he was just a good extra outfielder.

“He showed us that label is not valid. He’s become a guy who just doesn’t hit homers, but is a good situational hitter.

“Right now, you’ve got to put him right up there in the class of Van Slyke, (Brett) Butler, and (Lenny) Dykstra.”

Jackson’s defense--he has made only one error this season--also merits recognition with the league’s elite.

Said Padre Manager Greg Riddoch: “I know everybody talks about Andy Van Slyke, but I think our guy is as good as anyone in this league. He doesn’t have blazing speed, but his instincts set him apart from everyone else.”

But Jackson is considered by many in the Padre clubhouse as the key to their offense during the final 44 games. He’s responsible for making sure opponents keep pitching to McGriff. If they stop, Jackson must deliver.

“I still don’t look at myself as a No. 5 hitter,” Jackson said, “but if you look around out team, nobody else is either. Really, It’s been a whole lot of fun just trying to stay close to those guys (Sheffield and McGriff). It pushes you.

“They can make you look bad, and you don’t want to be the guy sticking out.”

Jackson ultimately can be responsible for helping Sheffield and McGriff be part of history this season. The Padres have the opportunity to have three players hit 20 or more homers in a season for the first time since 1970 with Nate Colbert, Cito Gaston and Ollie Brown. It also was the last year the Padres led the league in homers, and they currently lead the NL with 102.

“It’s nice to finally be recognized for what I can do,” Jackson, 28, said, “but I can honestly say I don’t expect anything in this game. I’ve always had to go year to year to see where I stand, and I can’t see that changing.

“I think the only difference is that I always thought I could wind up in Miami or Colorado in the expansion draft. I thought that’s what it would take for someone to give me a chance.

“I’ve got the chance, and I think people realize now I’m not bad.

“You know something, I even feel I belong.”