Like most successful people, Phil Rosenthal cherishes a little bit of dispensed wisdom that set him on the road to fame and fortune some years ago. Listen, kid, a grizzled veteran of the TV wars once told him: Do your show the way you want to “because the network will eventually cancel it anyway.”

And bingo, “Everybody Loves Raymond” was born – during a season (1996) when most prime-time newcomers were jostling to become the next “Seinfeld.” Rosenthal, creator and executive producer, did it his way and now “Ray” is CBS’ top dog sitcom (and a good bet to win an Emmy next month for best comedy).

And, we must also add, a most troubled show. The full cast of “Raymond” is expected to show up at the Warner Bros. lot this morning, assuming a deal can be brokered with holdout star Brad Garrett. His representatives and CBS were expected to work over the weekend to hammer out an agreement, which was widely expected by this morning. Most likely, they will all sit around the table and laugh at the preposterous events of the past few days:How Garrett refused to turn up because he wanted more dough. How other stars like Patricia Heaton, Doris Roberts and Peter Boyle quite suddenly and mysteriously came down with undiagnosed illnesses and also missed a few days. (They, too, are unhappy with their remuneration.) The giggles will have a hollow ring because intimations of mortality have descended on TV’s brightest sitcom. Nothing particularly funny in that.

Rosenthal, 43, is one of the key figures at the center of this mess and a more improbable villain you could not imagine. There apparently is not a soul who has ever met the disarming and sweet-natured Rosenthal who does not like him – particularly TV critics who have embraced him as one of their own. Yet, Rosenthal is about to do it his way again, and this time, “his way” has had a curdling effect. Both Rosenthal and co- creator Ray Romano want to end the show after this season, infuriating key cast members who re-upped for two more years (Romano for only one more) and who, residuals aside, stand to earn zip from syndication sales down the road. CBS apparently tried to mollify Garrett (earning an estimated $150,000 per episode to Romano’s $1.8 million) by offering him a spin-off show when “Raymond” disappears – nothing in writing, of course. But Garrett does not mollify easily.

So whom to blame? Probably no one. Successful sitcoms have built-in expiration dates, and “Raymond,” whether you like it or not, is fast approaching its own. There are a couple reasons for this, and the most obvious one is money. Cast salaries this season for the five key members will range somewhere between $60 million and $70 million (nearly $40 million for Romano alone), and that, of course, represents only a fraction of the above- the-line costs on “Raymond.” This means CBS stands absolutely no chance of making a profit on the 23 original episodes that will begin airing in September. For most successful sitcoms on commercial TV, the law of diminishing returns begins to set in right around the seventh season – which is why a show like “Frasier,” entering season 11 (its last), is a bizarre anomaly. How do big-time dramas such as “ER” and “Law & Order” escape this immutable law? One way is recycling the cast, over and over and over, to avoid holdouts (or holdups).

The other reason is a distinctly human one, and works this way: Producer X, after years of struggle and failure, finally gets a hit sitcom, and his phone begins to ring again. Network Y would like Producer X to sign rich development deal with Production Company Z. Producer X, being neither stupid nor naive, knows that his or her hit show will be forgotten in a few years and eagerly signs.

This happened to Rosenthal not once but twice, when he signed production deals with both Disney and Paramount. “Raymond” lost one of its key creative people, Jennifer Crittenden, to one of these honey traps a couple years ago. Rosenthal’s Disney deal yielded nothing, and that’s the story, so far, with Paramount. The heat’s on him to create new hits for CBS. (He’s got ideas for a sitcom and a drama.)

Meanwhile, the heat’s also on to keep “Raymond” around for a ninth season. And, yes, it’s intense. Not only does the cast want to extend its payday, but CBS, too, is looking to bank another 23 episodes in the syndication vault. Another year also buys time to groom a post-“Raymond” sitcom, and CBS – like every other network – has struggled to build sitcom franchises.

Why doesn’t Rosenthal just walk out of the kitchen? To his credit, he has pride of creation, and has stuck by “Raymond” ever since the day it was born (with low expectations) seven years ago.

And now, our fearless prediction: Romano and Rosenthal will forge a new agreement that gives each of the cast members a small slice of the syndication back-end profits. Then … drumroll … they will announce a ninth, and final, season.