After a tumultuous, injury-plagued season, many — if not most — Knicks fans would probably like to see Stephon Marbury sent on his way this summer with a buyout of the final year of his contract. Letting his deal age off the books, rather than using it to trade for another longer and bloated contract, just might bring the Knicks closer to a sane cap situation. But unless the Knicks plan on drafting a point guard with their lottery pick, fans may want to rethink their daydreams of Marbury’s departure from the Garden. If the Knicks don’t add any additional personnel, then the offense next season will suffer without him.

Yes, I’m serious, and this information surprised me too.

Earlier this week, I noted that the Knicks’ offense had declined in Offensive Efficiency (points per 100 possessions), despite the addition of Zach Randolph’s 17 points and 10 boards per game. That got me looking for a culprit. Part of the problem is that Randolph and center Eddy Curry clog the middle, preventing penetrations from the guards. Since January 1, the team has separated them, with Curry increasingly riding the pine. But, the Knicks’ offense, run by Jamal Crawford for the most part since then, still can’t hold a candle to the Knicks’ offense last season, run by Marbury.

The data is telling: The Knicks, in January and February, have an Offensive Efficiency rating of 103.1, which is in the bottom five of the league. Last season, their rating was 105.7, which was middle of the pack. The answer for the difference is simple. Crawford is a nice guy — his tendency to blow on his hands notwithstanding — but he’s not a point guard. And what’s more is that this isn’t the first time a team has discovered this fact. Crawford was drafted as a tall point guard by the Chicago Bulls in 2000 (for those who want precision, he was taken by Cleveland and swapped on draft night to Chicago for Chris Mihm), but he never worked out well at the position. In 2003, the Bulls drafted Kirk Hinrich and moved Crawford to shooting guard. Then in the following season, rather than re-sign him, the Bulls drafted Ben Gordon and worked out a sign-and-trade deal with the Knicks that sent Crawford to New York.

Crawford has had more success as a shooting guard in New York, but Marbury’s injury pressed him into point duty. He can’t quarterback a team. Although he has a good handle, he doesn’t work to space the floor effectively, nor does he utilize his effective crossover to drive the lane and create opportunities to pass the ball to teammates left open by the collapsing defense. Overall, he doesn’t look to create good passing angles. At present, Nate Robinson does more of this when he is on the floor running the point than Crawford does. Also, Crawford simply isn’t quick enough to keep most opposing point guards out of the paint. On four occasions Tuesday night against the Wizards, Antonio Daniels — hardly the quickest guard in the league — blew by Crawford en route to easy baskets.

So fine: Crawford is miscast (I strongly suspect that Jamal’s ideal role is as an instant offense sixth man), and he wouldn’t be the first guard to have point skills without actually playing the point well. But if the Knicks need a point guard and aren’t adding personnel, it would make more sense to have Marbury play and get some value out of him, rather than paying him to walk away.

Obviously, this is trying to make the best of a bad situation. The optimal scenario would be to have a new coach and general manager draft a new point guard, let Marbury walk as part of a symbolic purge of the Isiah Thomas administration, and use a portion of the mid-level exception for a veteran point guard (a Brevin Knight type).

The Knicks have played miserably, but every time I look at the roster, I can’t help but think that with better direction, they could be 10 games better in the standings. That is far from the heights some fans daydream of, but it is a giant step out of the depths that the team has called home for the last four seasons.

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It can’t hold a candle in hype quotient to the Shaq or Pau Gasol trades, but the San Antonio Spurs’ acquisition last night of forward/ center Kurt Thomas from Seattle for Brent Barry and Francisco Elson may be just as significant. With the conference elite getting bigger, Thomas, one of my favorite former Knicks (he often ate at Nobu — that’s how you spend an NBA salary), is still a stellar defender and a solid outside shooter. His work ethic will fit well into the San Antonio system. If Barry doesn’t find his way back to the Spurs via an immediate waiving, then newly signed Damon Stoudamire can take his role as long distance specialist.

mjohnson@nysun.com