Montana felt up to playing by game time, but his presence couldn't lift his team past the Giants. Despite having the league's best record, the 49ers were unable to pull away, and Montana was knocked out of the game in the fourth quarter. The Giants prevailed, 15-13, with a field goal on the game's last play.
New York went on to defeat the Buffalo Bills in the closest Super Bowl ever played, 20-19.
The Buffalo Bills were the class of the AFC in the early 1990s, advancing to four straight Super Bowls from 1990 to '93.
While they missed the playoffs in 1994, they won their division in 1995 and beat the rival Miami Dolphins in the playoffs' opening round, 37-22.
But days before their next game, against the Pittsburgh Steelers, defensive end Bruce Smith, who had made the Pro Bowl eight times up to that point and was arguably the Bills' best defender, caught the flu, keeping him out of the game.
Pittsburgh scored more points against Buffalo than anyone had all season, winning 40-21.
The Steelers advanced to Super Bowl XXX, where they were beaten by the Dallas Cowboys, 27-17.
The Bills have not won their division or a playoff game since.
The rivalry between the New England Patriots and the Indianapolis Colts became what was arguably the premier rivalry in the NFL so far this decade.
After Tom Brady took over at quarterback for the Patriots, they reeled off six victories in a row over the Colts between the 2001 and 2004 seasons.
But Indianapolis had won the last two games between the teams, leading up to a showdown for the AFC Championship after the 2006 season.
Rodney Harrison, the hard-hitting safety for the Patriots, came down with the flu a few days before the teams faced off. Harrison was not able to play.
The Patriots jumped out to a big lead early in the game and led 21-3 at one point before the Colts began scoring and pulled even.
Ultimately, the Patriots' defense wasn't able to stop the Colts, who emerged with a 38-34 victory.
The Colts went on to beat the Chicago Bears, 29-17, to win their first Super Bowl since 1970, when the team still played in Baltimore.
While the flu may have derailed their championship hopes the year before, the Patriots were able to overcome it in 2007.
Although the Patriots are notoriously guarded about how much the public knows about their players' ailments, quarterback Tom Brady was apparently suffering some symptoms when he led the Patriots over the San Diego Chargers to win the AFC Championship, 21-12.
Chargers linebacker Shawne Merriman was also apparently suffering from the flu in the loss.
In the week leading up to the Super Bowl, several members of the New York Giants, among them starting cornerback Aaron Ross, suffered some of the symptoms.
But it seemed everyone had recovered in time for Super Bowl XLII, a memorable game in which the Giants emerged victorious, 17-14.
Michael Jordan may be the most famous example of a flu sufferer to help lead his team to the title, but he wasn't the first.
After the Lakers captured the NBA championship in 1987, Lakers coach Pat Riley promised the fans of Los Angeles that he would deliver it to them again the next year.