If Super Bowl history has taught us anything, it's that the underdog can't always be counted out.
The 1985 Patriots and 1989 Broncos (Elway was on a magazine cover with the caption "we'll show up") notwithstanding, it's perfectly reasonable to think an upset is possible.
The Arizona Cardinals will try to make it two in a row, following the New York Giants' stunner over the New England Patriots last year.
They'll need discipline, spectacular play from unlikely sources, and probably a little luck to overcome the Pittsburgh Steelers' superior talent.
This is what the Cardinals' game plan should be.
It starts with quarterback Kurt Warner. The Cardinals' offensive line needs to ensure that Warner stays upright long enough to get his passes off.
Warner must help his linemen by making swift decisions and getting the ball out of his hands quickly.
Wide receiver Larry Fitzgerald should have few problems getting open, and if Warner's given enough time to hit him downfield, then a repeat of their three touchdown connections in the NFC Championship is possible.
Steve Breaston and Anquan Boldin will be secondary options, but they have to be ready to exploit any opportunities the Steelers give them by doubling Fitzgerald or blitzing Warner.
It might not be a bad idea for Warner to keep Steelers safety Troy Polamalu on his mind. As he's scanning his receivers, he should try to figure out what Polamalu will do if he throws the ball to a certain spot.
The Cardinals are a pass-first team, but they should make a serious commitment to the running game. Edgerrin James needs to carry the ball at least 15 times, even if he mostly gets short gains or no gain. The idea is to make the Steelers respect the running game.
The Steelers offense will be somewhat conservative, with QB Ben Roethlisberger handing the ball off, making a few key throws, and waiting for the defense to hand him good field position.
The Cardinals will have to get remedial on them: The first man to the ball carrier grabs him, stops his forward progress, and brings him down.
The Cardinals probably can't win without forcing turnovers. In their three playoff wins, the team has picked up four fumbles and snared eight interceptions.
They should look for more of the same Sunday, but not at the expense of solid, fundamental play.
That means no unnecessary gambling for interceptions by cornerbacks Dominique Rodgers-Cromartie and Roderick Hood.
Fortunately, the Cardinals' secondary seems to have gotten hot at the right time.
The Steelers won the Super Bowl three years ago, so they have plenty of experience at this level, including game MVP Hines Ward.
The Cardinals need not only solid play from Warner (himself a Super Bowl MVP with the St. Louis Rams) and veterans Darnell Dockett, Chike Okeafor, and Adrian Wilson, but also leadership from those guys when things go wrong early.
Coach Ken Whisenhunt needs to keep his charges focused on the raw essence of the game and not let them be overcome by all the hype and spectacle around them.
The Most Important Player
Edgerrin James. He has to force the Steelers to account for him on every snap, when they'd rather focus on his team's other stars. If he breaks a few long runs, he could get more attention than the Steelers want to give him.
That could free up Arizona's downfield threats and lead to an obligation at the trophy stand.