HOMESTEAD, Fla. -- Tony Stewart appears to be a lock to win the Winston Cup championship.

With a commanding 89-point lead over Mark Martin, Stewart is in the driver's seat.

So, why do two simple but disconcerting words -- What if? -- keep running through my mind as Sunday's season-ending Ford 400 draws near?

To be honest, I usually get nervous. So much has been written this week about how Stewart is so close to wrapping everything up, yet there has been little coming out of Martin's camp.

What if Martin is lying in wait, ready to pounce if Stewart makes a mistake? What if Martin has some secret gameplan that may knock Stewart for a loop?

What if several drivers band together to box in Stewart and keep him from making a run -- a form of payback for past run-ins?

In that same vein, what if Stewart is prematurely knocked out of Sunday's race before he's able to amass enough points to clinch the title?

I admit I'm as guilty as most other reporters, writing about the wonders of Stewart, how he's going to dominate Sunday's race, and how he'll turn the stretch run into a runaway.

But something Stewart said several times in recent interviews is troubling me -- and obviously causing him some significant concern, too.

"How many times do I have to tell you (reporters) that this thing isn't over yet? Eight-nine points is not unbeatable. Anything can happen," Stewart said.

And now Stewart has to fret about what could wind up hurting him more than any on-track mishap Sunday, yet he has no control over it. If I were in his shoes, I'd be starting to sweat.

You see, on Saturday morning in some office at Homestead-Miami Speedway, Martin, crew chief Ben Leslie, team owner Jack Roush and team president Geoff Smith will meet with a three-man board who will hear Roush Racing's appeal of the 25-point penalty Martin was assessed two weeks ago at Rockingham, N.C., for using an "unapproved spring" in the No. 6 Ford.

Also in attendance will be NASCAR technical officials who will present their side of the dispute. They'll explain why -- even though there was no malice or deception on the part of the team in the use of the spring -- that an illegal or unapproved part is just that: illegal and unapproved.

Led by George Silbermann, chairman of the National Auto Racing Commission, the three panel members will hear testimony from both sides, weigh the evidence and issue a final ruling.

And, if the board rules in Martin's favor, we have a brand-new ballgame entering Sunday's race. With the extra 25-point cushion he currently has, Stewart would have to finish at least 22nd to take home the title if Martin wins. But if those 25 points are reinstated to Martin's total, Stewart suddenly has to finish no lower than 13th if Martin wins.

That's a "What if" that has to have Stewart a bit nervous.

If Martin is indeed awarded the points, Stewart and crew chief Greg Zipadelli have to completely overhaul their strategy. For one, Stewart has to race for the win and nothing less. He can't sit back and coast, knowing if he stays out of trouble he'll still go home the winner.

And suddenly, even though he would still hold a 64-point lead at the time the green flag drops, the pressure on Stewart will be turned up several notches. While at the same time, Martin can race with a smile on his face.

Perhaps that's why we've heard so little from Martin and Roush team this week. They've been dutifully going about preparing Martin's Ford, not talking up a storm, staying quietly in the background and hoping Lady Luck is a Martin fan. Frankly, they've been conspicuous by their silence. If you didn't know it, you wouldn't think Martin was still in the title hunt.

But several things have to be going through Stewart's mind as Saturday's hearing approaches. He not only has to draw a line in his behavior between being confident and cocky in his approach to Sunday's race, he also has to keep in mind two drivers other than Martin.

First is Bill Elliott. He'll be the first to tell Stewart that no lead in a title chase is safe. Elliott was leading the points heading into the season finale at Atlanta in 1992, only to have the late Alan Kulwicki come from behind and steal the crown away.

And then there's Sterling Marlin. Had he not suffered a season-ending neck injury six weeks ago, the battle would likely have a much different look. Marlin had spent 25 consecutive weeks atop the points and, even though he dropped to fourth at the time of his mishap, was still one of the men to beat in 2002.

Stewart knows the unfortunate circumstances that befell Marlin, circumstances that could easily have been cast upon Stewart instead. And those circumstances can still befall him Sunday, either of his own doing or by the doing of some other driver.

That's why Stewart has to focus on so much more than Martin. Why, right now, Martin could be one of the biggest sleepers in NASCAR history. He has nothing to lose and everything to gain. He can afford to drive a race that Stewart can't.

And that could be the biggest unanswered "What if?" of all.

Jerry Bonkowski covers NASCAR for ESPN.com.