CRACKS IN DODGERS', PADRES' FOUNDATIONS.

Byline: TIM BROWN 

There is a small, brown patch of dirt, surrounded by shiny green plastic and great, gray gobs of concrete, that might very well determine the destiny of the National League West.

Otherwise ordinary, this regularly raked earth on South Broad Street in Philadelphia hosted two events separated by five days that both disintegrated the San Diego Padres and weakened the Dodgers. When September finally does arrive, second base at Veterans Stadium might have had the final say.

On May 28, Dodgers catcher Mike Piazza, the key figure in the Western Division, lashed a line drive off the top of Veterans Stadium's right-field wall. Running on what already was a mildly sore right knee, Piazza slid late and awkwardly into second base, caught his right foot on the bag and tore a piece of cartilage.

On June 2, Wally Joyner, the poster boy for the Padres' startling participation in the West, broke from first base on a ground ball in the fourth inning. He attempted to break up a double play, instead broke up his thumb, and second base at Veterans Stadium had its second victim.

At that moment, the Padres had a 35-20 record, a 102-victory pace. Into this weekend, they were 40-39, and 5-19 since second base rose up on Joyner. Though Padres manager Bruce Bochy has characterized the sudden wobble as ``a team effort,'' because of injuries and the second-time-through-the-league syndrome for his bullpen, Joyner's .321 batting average and 16 doubles went a long way toward explaining what the Padres were doing. His absence - it could extend into late July - might also explain what they're not doing anymore.

The effects on the Dodgers are not so obvious, but there nonetheless. Piazza has not played in six of the club's last 27 games, and has batted .288 since he hyperflexed the knee. He cannot run hard to first base or, for that matter, to second base. He has six doubles in 260 at-bats, or twice as many doubles as pitcher Hideo Nomo has in 31 at-bats. Piazza also is noticeably more limited behind the plate, where he is slow and creaky out of his crouch.

Including the game in which he was injured, the Dodgers have won half of their last 28 games, and only four of 10 since the Padres tumbled past them and into the middle of the West's pack. The Padres and Dodgers begin a three-game series in San Diego on Monday.

Beware the bag.

No fat pitches: There was some resignation this week in the words of Bret Saberhagen , who had reconstructive surgery on his right shoulder a month ago and, if he chooses, faces yearlong rehabilitation with an uncertain outcome.

Saberhagen, who intends to return to the Colorado Rockies in August for his first steps back, told The Denver Post that he and his shoulder will return to baseball at full strength or they will not return at all. There's no Frank Tanana in Bret Saberhagen.

``If I can't throw 90 mph,'' Saberhagen said, ``then I hope I can throw 70 mph to my kids.''

There is a real chance that he will come out the other side of the surgery with a fastball closer to the latter figure.

``I've accomplished a lot,'' he told the Post. ``I'm not disappointed. A lot of people would love to have the career I've had. I'm real satisfied with my early years. In the later years, there have been a lot of injuries. Maybe that goes with age. There's been a lot of wear and tear.''

Saberhagen is 32.

Is that `chip' or `chop'?: Perhaps the game's best athlete now that Bo Jackson and Deion Sanders no longer hang around, St. Louis Cardinals outfielder Brian Jordan had three hits against the Atlanta Braves on Wednesday. A former defensive back, Jordan once was released by the Atlanta Falcons.

``I have a chip on my shoulder against Atlanta,'' Jordan said. ``I guess I take it out on the Braves.''

Add Braves: In all of the commotion over Greg Maddux's sudden bent toward mediocrity, Steve Avery's June was nearly lost. He probably would prefer it that way. In his last five starts, Avery has allowed 44 hits and 30 runs in 25-2/3 innings, a 10.71 ERA. He has not won since May.

Hit parade: Montreal Expos second baseman Mark Grudzielanek, who has 105 hits, could be the first National League batter to go over the 200-hit mark since 1989, when Tony Gwynn had 203. Grudzielanek missed three games this week to attend his grandfather's funeral in Milwaukee.

It might work: Rick Aguilera, attempting to make a successful transition from closer to starter for the Minnesota Twins, allowed 10 runs in three innings to the Seattle Mariners on June 15. Well, good idea, bad result.

But not so fast. Aguilera has allowed a total of four runs in his last three starts, over 22-1/3 innings.

Falling O's: For two reasons, the Baltimore Orioles are beginning to lose touch with the New York Yankees in the American League East.

Into the weekend, Roberto Alomar was hitless in his last 14 at-bats and was 13 for 69 in the Orioles' last 19 games. A .400 average doesn't seem all that realistic anymore.

Also, the Orioles are 31-13 against teams with losing records, but 9-22 against good teams.

Pulling up his Sox: In the American League Central, Darren Lewis is doing his part, and a few others', to prolong the White Sox's improbable attempt to unseat the Indians. He is batting .371 with 22 runs and 24 RBI in his past 32 games.

Notes: Bill Russell might have an understated manner, but there is something very managerial about his style. Don't count him out in the campaigning for Tom Lasorda's job. . . . The Chicago Cubs have won consecutive season series from the Dodgers for the first time since the 1971-72 seasons. . . . Cleveland Indians catcher Sandy Alomar, whose career has been fairly chewed up by injuries, played his first game at first base on Thursday. . . . Boston Red Sox catcher Mike Stanley has thrown out only four of 54 base-stealers. Is anybody holding those guys on? . . . Mets first baseman Rico Brogna will decide Monday on shoulder surgery which could end his season. . . . The A's already have 120 home runs, more than any of Art Howe's four Astros teams had in a full season. . . . Padres third baseman Ken Caminiti will have surgery on his left rotator cuff after the season. Recovery could take up to nine months.

MEMO: Staff Writer Tim Brown's baseball column appears Sundays in the Daily News.

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Photo

Photo: Mike Piazza's indispensability to the Dodgers became apparent the instant he tweaked his knee.

Daily News File Photo