Lastings Milledge is a fraud.

I’ve been putting off writing this column for a while, but with Carlos Beltran having all of three at-bats since April 15 due to a tight hamstring, it’s looking like he’s going to have to go on the disabled list. If he does, Endy Chavez, whose .231 batting average vastly overstates the contribution he’s making to the Mets’ offense, will continue to be the regular center fielder. That’s not good. And with Milledge hitting like Ty Cobb down in Norfolk (.400 AVG/.522 OBA/.622 SLG),a lot of pressure is building to bring him up, stick him in the lineup, and leave him there. The hopeful Mets fan dreams of Xavier Nady being a top pinch-hitter and Cliff Floyd insurance, and of Milledge joining David Wright and Jose Reyes in subway ads touting the Mets’ young, homegrown stars.

Unfortunately, Milledge just isn’t that great a prospect. I realize that in offering this opinion I go against the judgment of everyone from Baseball America, which had him as the ninth-best prospect in the game entering the season, to Baseball

Prospectus, which had him as the 13th best, to the Mets, to Mets fans who are convinced that Beltran ought to be studying the career of Wally Pipp with special attention right now. Such, though, is my judgment.

How can this be? Milledge, after all, just turned 21 and is laying waste to Triple-A. Last year, he pounded the ball for a .337/.392/.487 line in 193 at-bats after a promotion to Double-A. He has speed, a sterling defensive reputation in center, and a pedigree dating back to when he was considered the best high school position player in 2003. He’s also looking like he’s learned how to take a walk, having already drawn as many in 21 Triple-A games as he did in 48 Double-A games. Youth, tools, performance at a high level, and all at a key defensive position. It’s not hard to see why everyone’s so excited about this guy.

There are two problems, though. Players like this flame out all the time, and Milledge’s gaudy numbers hide an ugly flaw in his game.

Let’s address the second problem first. Milledge can’t hit for power, and he probably never will. Yes, he’s slugging .622 in Triple-A, but that’s because he’s hitting .400 with a bunch of doubles and triples, which are functions of speed (of which he has plenty) as well as power. Last year, in 232 at-bats in high-A ball, he hit .302/.385/.418. Dating back to the beginning of last year, he has 495 at bats, in which he’s hit all of nine home runs. Nine! That’s a season’s worth of at bats at high levels, and he hasn’t broken double digits.

The usual response here is to point out that he’s young and has great bat speed, and so his doubles will inevitably turn into home runs. This is like saying a young pitcher who throws 97 mph will inevitably develop his control: It would be nice if things worked that way, but they usually don’t. Most of the time, a player is at 20 pretty much what he’s going to be for the rest of his career, just less so.

This isn’t some small flaw in his game. It’s not 1906 anymore. Even gifted defensive center fielders have to be able to knock the ball out of the park. Jose Reyes hit five home runs in Triple-A and the majors when he was 20. Able to slug .418 in A-ball if he can maintain a .300 average, and possessed of slightly more home run power than Reyes at lower levels at the same age. That’s Milledge.

How do players like this develop? The most sophisticated publicly available system for projecting player performance is Baseball Prospectus’s PECOTA, which breaks down a player’s stats in various categories – everything from batting average to groundball percentage – adjusts for offensive environment, age, and body type, then finds comparable players. Reyes comes out as similar to guys like Luis Aparicio and Barry Larkin, David Wright to guys like Jim Fregosi and Dick Allen, and so forth. To whom does Milledge – a historically common type of player – get compared? Ruben Mateo.

You may remember Mateo, a top prospect with the Rangers in the late 1990s. He was – stop me if this is familiar – a highly regarded five-tool prospect who started to put it all together at 20, hitting .309/.358/.522 (with 18 home runs, I might add) in Double-A. At 21, he mauled Triple-A, hitting .336/.375/.597, matching the previous year’s home run total in about half as many at-bats, and earned a call-up to Texas, where he hit .238 with no power. The next year he got hurt. He’s now played for four major league teams and has a career on-base average of .303.

Another figure for comparison is Jackson Melian, once a highly regarded Yankees prospect. Melian has yet to play in the majors. Most of the rest you’ll never have heard of; Vernon Wells and Milton Bradley are by far the most successful, and those two probably represent Milledge’s ceiling. Being compared to Wells is no bad thing, but Milledge has a much greater chance of turning into the next Mateo or Alex Escobar.

Can Milledge help the Mets right now ihmf Beltran finally goes on the DL? Sure.He’s a better hitter than Chavez (of course, so is Rey Ordonez),and there’s no reason to think he’s not at least as good in the field. Past that, his true value is probably as trade bait. Unless he develops a lot more power, he’ll probably have to hit about .310 to be a really good major league right fielder. You know how many players hit .310 last year? Eleven, and half of them are going to the Hall of Fame someday. I still don’t think the Marlins are going to trade Dontrelle Willis this year, but if I were Omar Minaya, I’d have them on speed dial.

tmarchman@nysun.com