They're Westchester County, N.Y., neighbors, the same agent represents them and, less than four years ago via a blockbuster trade two weeks after his hiring, Thomas made Marbury the centerpiece of his rebuilding program.

Yesterday, their marriage hit the rocks, perhaps taking an initial step toward divorce when Marbury flew back to New York before the Knicks' trip-opening game in Phoenix, skipping both the morning shootaround and a 113-102 loss to the Suns.

Thomas wouldn't specify what precipitated yet another Knicks crisis/distraction. However, one NBA player familiar with the situation said punches were thrown during Monday's flight to Phoenix, and someone who was on the flight admitted awakening to a commotion as Thomas discussed his dissatisfaction with Marbury's play and a possible demotion from the starting lineup.

If that's the case (and Knicks' officials deny a fight took place), Marbury probably has played his last game for his hometown team.

Thomas also wouldn't say whether the 30-year-old Coney Island product will be suspended or fined. The latter could cost Marbury more than $180,000 of his $20.1 million salary for each game he misses.

Marbury, according to several reports, said he had Thomas' permission to return to New York, but the Knicks' president-coach wouldn't address that either, calling it "an in-house matter," a phrase he used at least 15 times yesterday.

But Thomas did say, "He is welcome back and we want him as a member of this team."

As the starting point guard?

"If he does the things that I want him to do, yes," Thomas said.

"We need leadership from that position at the point guard and we also need defense. Those are two things that he's definitely capable of doing. . . . Those are the only two things that I require from that position."

Based on how often guards such as Allen Iverson, Jameer Nelson and Jason Williams blew by him on drives the previous three games, plus a benching for more than a quarter during the second half of the Knicks' opening-night loss in Cleveland, Marbury (15.2 points, 6.8 assists) hasn't met Thomas' defensive criteria.

His lack of leadership can't be chronicled as easily, although he and Quentin Richardson nearly came to blows two seasons ago — and Richardson questioned his teammates' focus after Sunday's loss.

A number of players on the Knicks — who also played yesterday without Richardson (elbow) and Zach Randolph (bereavement) — declined comment on the matter. But both Jared Jeffries (active for the first time this season) and Mardy Collins (who started for Marbury) said their teammate would be welcomed back if and when he returns, even though he essentially walked out on them.

"You always support your teammates," Jeffries said. "Nobody knows circumstances. If it's not happening to you, you can't judge."

"I don't have one bad thing to say about Steph," Collins said.

Phone calls to Marbury were not answered yesterday, nor were messages left with his (and Thomas') agent, Jordan Brezant. Marbury has a home in Los Angeles, where the Knicks play the Clippers today, but isn't expected back by then, according to one report.

The two years (including this season) and $42 million left on his contract, meanwhile, mean a buyout would cost the Knicks plenty, barring the unlikelihood of him settling for a far lower figure.

That contract and his history (Minnesota, the Nets and Phoenix previously unloaded him) also make it difficult to trade him at this point — although the closer he gets to the final year of his contract (worth $21.9 million next season), the more appealing he becomes to a team seeking expiring contracts to create salary-cap room.

Marbury has been a lightning rod for criticism at least the past three-plus seasons, particularly after he declared himself the league's best point guard before a Jan. 1, 2005, game against the Nets and Jason Kidd. The Knicks' won-lost record since then: is 75-148.