METS PUSH BACK PEDRO'S RETURN  —  The pitching help that the struggling Mets could use most - three-time Cy Young winner Pedro Martinez - won't be arriving anytime soon.  —  GM Omar Minaya told The Post the Mets now expect a strained left hamstring to sideline Martinez until at least the middle of May - and possibly into June.

Tribe closer says he ‘had nothing’  —  Joe Borowski doesn't know what's wrong.  One day he feels like he can throw the ball through a brick wall.  —  “The next day, I feel like I'm throwing through water,” said Borowski.  —  Monday night, Borowski should have come to the mound …

Brewers supposedly have signed Weaver  —  I received a tip from a reliable source this morning that the Brewers have signed free-agent right-hander Jeff Weaver to an incentive-laden deal.  —  I'm traveling to St. Louis this morning and won't be able to get it confirmed with club management until later …

JORGE MULLS HIS OPTIONS  —  Jorge Posada is mulling the pros and cons of getting a cortisone shot in his ailing right shoulder.  —  “It's 50/50 it would work because of where the problem is,” Posada told The Post during batting practice last night at Tropicana Field.

Schilling laughs off Yankee talk  —  Red Sox pitcher Curt Schilling reiterated this morning his previous assertion that he would not consider pitching for the Yankees next season, despite comments to the contrary from his personal doctor.  —  “[Schilling] called me when he was angry …

Jeter talks about Jackie Robinson  —  Yankees shortstop discusses importance of No. 42  —  Derek Jeter was growing up in Kalamazoo, Mich., when he first heard the name “Jackie Robinson” from his father, Dr. Charles Jeter.  In the years since becoming a Major League Baseball player …

Money not buying happiness for Yankees, Mets  —  The Mets and Yankees have spent a combined $346,874,953 on ballplayers for the 2008 season.  So far, this is what it has gotten them: 12 wins, 13 losses, third place in the National League East and fourth place in the American League East.

One-game playoff won't be forgotten  —  Rockies, Padres fought for 13 innings for Wild Card berth  —  The Rockies rejoiced and the Padres went home.  —  One moment, two teams and a season defined for both that became indelible stamps that fans of each franchise will remember forever.

Chamberlain Leaves Yanks to Join His Ill Father  —  ST. PETERSBURG, Fla. — Part of the budding legend of Joba Chamberlain is his close bond with his father, Harlan.  For several games this season, at home and on the road, Harlan Chamberlain has been around the Yankees …

How will ball tracking analysis change the game?  —  One of my favorite baseball books is Pure Baseball by Keith Hernandez.  It is an in-depth look at two games from the 1993 season, at-bat by at- bat, pitch by pitch, with Hernandez as the narrator and baseball teacher.

Number of black MLB players drops to 8.2 percent  —  ORLANDO, Fla. — Major League Baseball received its best grade for racial diversity in hiring, even as the percentage of black players dropped again last year.  —  MLB received its first A-minus for race Tuesday from Richard Lapchick …

Pitching Mechanics: Clay Buchholz  —  Red Sox phenom Clay Buchholz is one of the most-watched pitchers this year as Boston fans hope to see more of the outstanding stuff that he showcased in 2007, throwing a no-hitter in just his second major league start.  Everyone knows that Buchholz …

Trade hasn't hurt Marlins in standings  —  They're watching the standings in both leagues.  They see that they're in first place and the Detroit Tigers are in last place.  —  There's a feeling of pride, for sure, but no one on the Marlins is gloating.  —  “They've got their hands full …

Piazza Coming To The Bronx?  —  Up until the last few days, Yankees' GM Brian Cashman has often resisted the temptation of putting Mike Piazza in pinstripes.  But with his current catching situation (and don't forget prospect Francisco Cervelli is still out with a broken wrist) …