MLB

Yankees, Mets farm systems must develop pitching depth

In the last week, it became more important that Mike Pelfrey matures into a top-flight starter for the Mets, and Phil Hughes does the same for the Yankees. In the last week, it became more problematic that Jenrry Mejia is in the bullpen — and maybe Joba Chamberlain, too.

That is because in the last week Josh Beckett signed a long-term extension with the Red Sox and Yovani Gallardo did the same with the Brewers. That continued a trend of diluting the starting pitching free-agent market in upcoming years. It was not long ago, for example, that Beckett, Roy Halladay and Tim Hudson were going to be part of the free-agent class after this season.

Now just Cliff Lee is the lone elite starter projected into free agency, and he begins this season on the disabled list dealing with foot and oblique issues. The next best is Javier Vazquez, followed by even more dubious pieces such as Jorge De La Rosa, Ted Lilly, Kevin Millwood, Brandon Webb and Jake Westbrook.

It does not get better in subsequent years. There is a dearth of available prime-age aces as teams have more proactively bought out free-agent years with extensions for their elite starters. In the past two offseasons, Kansas City’s Zack Greinke and San Francisco’s Matt Cain have signed through 2012, Florida’s Josh Johnson and the White Sox’s Gavin Floyd through 2013, and Seattle’s Felix Hernandez, Boston’s Jon Lester and Detroit’s Justin Verlander through 2014.

So the spigot is just about off for high-end, 30-and-under starters coming out in free agency in the next few years. Of course there will be trades. It is not hard to imagine, for example, that the Royals recognize they cannot keep Greinke through another extension and deal him for a boatload of prospects.

Still, the market for premium pitching is going to be shallow and, thus, through simple supply and demand, very expensive in giving up prospects, dollars or both. Thus, teams not developing organizational pitching depth will face major problems. So how are the New York teams stacked up? Let’s take a look:

METS

They lack organizational depth, so they do not have a lot of margin for error. The best-case scenario would have Johan Santana, Pelfrey, Mejia and Jon Niese forming a strong foursome moving forward.

The Mets continue to believe that Pelfrey is going to grow into a No. 2 starter, specifically because of the development of his splitter. And they think Niese is no worse than a No. 4, and better than that as his cutter improves. They privately insist Mejia’s bullpen foray is short-term and that he is a starter. But having him in the pen now could retard his development and keep him from building up to starter innings any time soon.

And if anything happens to that front four, the Mets’ future could become far worse. At this point it is obvious that John Maine and Oliver Perez are not part of any future planning. The Mets like power-armed Brad Holt, but many other organizations are not as high on him. The Mets think Tobi Stoner could be a complementary piece at the back of a rotation, but they felt that way last year about Dillon Gee and he regressed significantly.

Beyond that the Mets have arms they like, but they are far away. Kyle Allen, Jeurys Familia and left-hander Robert Carson are in the A-level Florida State League, but several organizations like Carson’s groundball penchant. Every other team in the division is arguably better positioned for the near future with their rotations, including the Nationals who have Stephen Strasburg coming from the minors and Jordan Zimmermann recovering from surgery.

YANKEES

Hughes is vital. Vazquez can leave as a free agent after the season and one of these years Andy Pettitte actually will retire. That would leave the heavy workload of CC Sabathia and the hard-to-rely-upon A.J. Burnett in place moving forward. So having Hughes develop into a No. 3 starter is important, especially because the Yankees seem to believe now that Chamberlain is a reliever.

The Yankees also were placing great hope that at least one from the group of Christian Garcia, Dellin Betances and Andrew Brackman would begin a steady rise toward the majors because they have the stuff — if healthy and developed — to pitch near the top of a rotation. But the oft-injured Garcia ruptured the ulnar collateral ligament in his right arm in his Double-A opener, and likely will undergo season-ending Tommy John surgery.

Beyond that the Yankees are seeing the benefits of a philosophy shift. The big-pay-for-nothing they received from Carl Pavano and Jaret Wright convinced the organization that it must do a better job filling the organization with arms that can be — at the least — inexpensive, back-of-the-rotation filler. And the Yankees are loaded with such possibilities, including Alfredo Aceves and Sergio Mitre in the pen.

And the Yankees believe some members of that depth group can graduate to better than that, notably Ivan Nova, Hector Noesi, Adam Warren, Jairo Heredia and Manuel Banuelos. They also have a positive vibe about Jeremy Bleich, Zach McAlister, Ryan Pope and David Phelps.

And in the AL East, the Yankees will need the sturdy pitching just to keep up. The Red Sox locked up Beckett and Lester, signed John Lackey for five years in the offseason, plus have Clay Buchholz now and Casey Kelly coming. The Rays control James Shields, Matt Garza, David Price, Jeff Niemann, Wade Davis and Jeremy Hellickson through 2012 at minimum. And the Orioles are beginning to see their patience with pitching prospects blossom with Brian Matusz, Chris Tillman and Brian Bergesen in the majors, and Jake Arrieta and Zach Britton close behind.

joel.sherman@nypost.com