Rob Johnson has made only seven starts in his NFL career. That number would be higher if the Bills QB could stay healthy.

The Buffalo Bills, come to think of it, once did things this way. Otherwise, Doug Flutie would still be biding his time behind Rob Johnson, you'd never have plunged a spoon into a bowl of Flutie Flakes, and as for last year's playoff run, who really knows?

But Johnson did go down, with a veritable cornucopia of maladies, early and often in the 1998 season. And in a recurring theme, he continues to do so.

The difference? Here in 1999, there is no Flutie behind him. And that is precisely what makes the Bills feel so vaguely vulnerable just about now.

Flutie is the starter these days with the Bills, but you knew that already. Most of the sports-watching world was galvanized by Flutie's 1998 season, a storybook thing in almost every respect. No news here.

But Rob Johnson -- this guy matters, and in a way that is so very peculiarly football. And without wishing bad fortune on anyone, it isn't entirely a stretch to suggest that the Johnson angle could play its way back into the Buffalo story before too long.

Tonight's test for the Bills, against the Dolphins in Miami, works as theater on about a dozen levels. It's a rematch of last year's AFC wild-card game, won by the Dolphins 24-17, and it is played out against the constant companion theme of Dan Marino's potential last great stab at glory. And, of course, it's the Dolphins and the Bills, which is good for something just about any day of the week.

But the undercurrent at Pro Player Stadium tonight, however mild its tug, has to involve the Flutie-Johnson situation on some level. Put it simply: Miami brings perhaps the most vicious defense in the NFL. The Dolphins would be silly not to get after Flutie early and often. And if Flutie were to leave the game ... what?

What? Excellent question, and one that the Bills haven't had to concern themselves with since Flutie took over in Game 5 last year. Smallish but durable, mobile to the point of escape, the former CFL star can make Wade Phillips' offense work in Buffalo while on the run.

And good thing, because if this gets down to Johnson, we're all in trouble. The Rob Johnson injury file is the thickest thing about the man right now, and there's nothing remotely funny about it.

In 1997, it was an injured ankle. In 1998, Johnson suffered a concussion in Game 1, another one in Game 3 and the torn rib cartilage in Game 5 that opened the door, however darkly, for Flutie.

Last week against Philadelphia in a spot-duty situation, Johnson absorbed a brutal blind-side hit by the Eagles' Mike Mamula and suffered a mild concussion. If this is the depth chart, it's time for Phillips and Co. to start talking about No. 3.

It's amazing what has happened to Johnson in the span of barely 12 months. If he doesn't go down so early in the '98 season, he probably remains the Bills' starter to this day -- and, sure, injuries are a part of life in the NFL. But Johnson looked, before all this unhappiness, like a quarterback getting ready to do some great things. Instead, some great things have been done unto him.

Buffalo is out of the gate at 2-1, but the Bills' chances this season seem so obviously tied to Flutie that it's hard to see past it. Like the Jets and Vinny Testaverde, Buffalo is a team that appears to rest one key injury away from rampant mediocrity.

Difference is, this is a team with a genuinely skilled backup quarterback, the kind of modern-game luxury that franchises used to take for granted. Bitter irony: The backup is the guy they can't keep healthy. It don't come easy.

Mark Kreidler is a columnist for the Sacramento Bee, which has a web site at http://www.sacbee.com/. During the 1999 NFL season, he will write a weekly column for ESPN.com, focusing on the Monday Night Football matchup.