Leave it to Gary Sheffield to torpedo his own trade value. From the NY Post’s Michael “Heaven Knows I’m Miserable Now” Morrissey.

Sheffield blasted numerous Yankees targets last night, insinuating Brian Cashman was one of many Yankees “middlemen” to George Steinbrenner, once again questioning Joe Torre’s lineup shuffling and minimizing Bobby Abreu’s ability. Perhaps most troubling to fans, he argued that if Steinbrenner was still in good health, he’d be back in the fold for 2007.

Instead, he’s angry trade bait, run out on a rail because of Abreu.

“He’s a good player,” Sheffield said. “But like I say, you can draw it up any kind of way: He ain’t me. And that’s the bottom line.

“I understood them having to make this move for the remainder of the season. But to sit there and I’m leaving because of [him], I was always told you leave because somebody’s better than you. I don’t think that’s the case here.”

Sheffield acknowledged he was Alex Rodriguez’s sounding board last season. Asked who would take his place, he answered, “Nobody,” a seeming shot at Derek Jeter and other team leaders.

“You all better get ready,” Sheffield said. “There’s nobody.”

“They can’t tell me what to do,” Sheffield said of the Yanks. “Trust me. I’m my own man.”

Two different major-league officials believed Sheffield will end up with the Cubs or Athletics. The Padres are also in the mix, but the Astros aren’t. Sheffield said he didn’t speak with Steinbrenner in Tampa because of the 76-year-old’s health, but he thinks he would be a Yankee in 2007 if the owner was feeling better.

“I know I would be here,” he said. “Because when you have middlemen blocking him and won’t let you do certain things, they get in the way and their personal feelings get in the way, that’s what happens.

“You know who the middlemen are. You all talk to them every day.”

Along with reporting no news on the Tom Glavine front (“Tom is a very thorough and thoughtful person,” says his agent), the Newark Star-Ledger’s Don Burke reports that Mark Mulder — he of the partially torn rotator cuff — has expressed interest in joining the Mets, citing his past love affair with pitching coach Rick Peterson.

Fish Stripes scoffs at talk of the Marlins trading the D-Train to the Mets, writing “if the Mets want to eat all of Delgado’s and Lo Duca’s salary and send Milledge and Heilman along with them in the trade, then I think the team may be interested.” Because after all, Florida’s already shown they’ll hold out for proven, major league talent when dumping trading their franchise players.