Oh, no, Isiah. Not this.

When Seattle Sonics center Jerome James blew up in the first round of the playoffs against Sacramento, averaging 17.2 points and 9.4 rebounds, my first thought was, “Some moron is going to give him $30 million for this.”

My second thought was, “I hope it won’t be Isiah Thomas.”

Unfortunately, in the New York Knicks’ quest to fill their need for a center, Thomas fell for the lure that has roped in so many other NBA execs in recent seasons: a deceptively promising center who can’t play.

And make no mistake – James can’t play. While he tortured Sacramento’s porous frontcourt in Seattle’s first round win, he turned in his usual subpar performance against better opposition in Round 2, averaging 8.5 points and 4.7 rebounds in the Sonics’ six game defeat to San Antonio. And even those numbers would be career highs for him over the course of a full season.

For more conclusive evidence that James will be stealing the Knicks’ money, look at his past three seasons, during which time the 7-foot-1-inch behemoth has been a monument to mediocrity. My Player Efficiency Rating (or PER, which I use to measure a player’s per-minute overall statistical performance) showed James to be the NBA’s 58th-best center in 2004-05 with a rating of 9.8, which is right behind such luminaries as Melvin Ely, Jason Collier, and Greg Ostertag … not to mention former Knick centers Dikembe Mutombo, Nazr Mohammed, and Othella Harrington. James’s prior two seasons were a bit better at 13.1 and 11.3, but at no time has he even threatened the league average PER of 15.0.

The first of many downsides is that despite his size, James is a very poor rebounder. He rebounded 11% of missed shots when he played last season, ranking him 59th among the league’s centers. In other words, he’s not going to help the Knicks much on the boards – especially since he’s replacing Kurt Thomas, who averaged double figures.

James is also amazingly turnover prone – partly because he fancies himself a guard, though one with a 1/3 career assist-to-turnover ratio. What’s more, his poor work habits don’t figure to improve now that he’s guaranteed a steady income for the next five years.

Can he defend? Sure, when he’s motivated. That’s James’s one legitimate skill – with his size, he’s a good post defender, and that’s certainly an asset the Knicks can use. Unfortunately, Isiah didn’t research how long he’d be able to use that asset each night. Between James’s poor conditioning and rampant propensity for fouling, it’s all but inconceivable that he’ll stay on the court for more than half the game. In fact, he played only 16 minutes a game in 2004-05, but nearly led the league in personal fouls.

And let’s not forget about that motivation issue. This is the same guy who responded to a coach’s complaints about selfish players with the infamous quote, “I don’t have the first clue who he is talking about, because all I worry about is Jerome.” Herb Williams must be in stitches.

Finally, there’s the age factor. If James isn’t a good player at age 29, what’s he going to be like in five years? Suffice it to say that James figures to be the Knicks’ next Allan Houston, collecting checks from the end of the bench while management begs him to retire. And, um, wasn’t this team supposed to be rebuilding? Does this fit with the plan? Speaking of plans, didn’t Isiah want the Knicks to be a running team? And isn’t James among the slowest players in the league? My brain hurts.

But let’s play devil’s advocate for a minute. The Knicks needed somebody to play center, and with Kwame Brown off the market, wasn’t James the next-best option? Not even close. You want somebody better? Here are several, all of whom would have cost a fraction of what the Knicks will pay James:

* Chris Andersen If Isiah hadn’t been so hung up on Kwame Brown, he could have nabbed the “Birdman” from New Orleans at the start of free agency. Andersen is one of the league’s top shotblockers and shot 53.4% from the floor. Plus, his PER of 18.5 bested that of every Knick except Stephon Marbury. Instead, Andersen quickly re-signed for a pittance with New Orleans.

* Zaza Pachulia This is the one that should really make Knicks fans verklempt. The Bucks’ backup center is only 21, has a great touch around the basket, and will probably be a steal now that Milwaukee has drafted Andrew Bogut and re-signed Dan Gadzuric. In fact, the Knicks probably could have acquired Pachulia in a sign-and-trade, allowing them to keep their mid-level exception to use on another player. Like maybe ….

* Fabricio Oberto Unlike the Knicks, the Spurs actually know what they’re doing and reached an agreement on a three-year deal with the skilled 6-foot-10-inch Argentinean the same day the Knicks were proudly paying twice as much for James.

* Steven Hunter Reports say the Knicks were first interested in Hunter but cooled on him so they could sign James. If that’s true, Isiah should be fired immediately. Hunter is an athletic finisher and shot-blocker who shot 61% last year, and he’s only 23.

* Ken Bannister Okay, I’m exaggerating a bit now, but once New Yorkers see James’s repertoire this winter, they are going to start wondering if bringing The Animal out of retirement could have been any worse.

The deal for James ranks right up there with the signings of Calvin Booth, Jim McIlvaine, Michael Olowokandi, and Adonal Foyle among the worst big man acquisitions of the past decade. If there was any doubt that Isiah’s reign is doomed to failure, this move put it to rest. The Knicks are out $30 million and have once again hampered their ability to get under the salary cap some time before the end of the century.

Oh, yes, and one other thing: They still don’t have a center.