Each year, the flu leaves many bed-ridden and unable to get to work. And while you might worry about how your co-workers will feel about the time you miss, it's unlikely you'll have to worry about disappointing hordes of fans.
But star athletes do: The virus has changed the course of championships, either in the form of missed opportunities or plays made even more memorable for what players overcame.
"Fans are not forgiving of athletes for being human," said Dr. Rebecca Jaffe, a family and sports medicine physician in Wilmington, Del., speaking of her own experiences with New York- and Philadelphia-area fans.
"They shouldn't put their overall health at risk to do something that will limit or compromise their well-being."
So some athletes make it out to play, while others have their doctors recommend staying home.
"It depends on the severity of it," said Dr. Scott E. Nelson, a family physician in Cleveland, Miss. "Milder cases of the flu, we've seen all sorts of athletes in different sports make it happen."
How well athletes respond may also depend on whether they've had flu before.
"If you get the true flu, you feel like you've been hit by a truck, so you're not likely to get up and exercise," said Jaffe.
"[An athlete] might have been exposed to the flu previously, and therefore had some antibodies. He may have had a milder case and been able to rise above it," she said.
Athletes who sit out the game may decide they won't be in top form.
"I think a fan's sympathy, at least from me, as both a fan and physician [is that] if someone's got the flu and they don't want to play, they're doing it because they don't want to hurt the team," said Nelson.
That may be something to keep in mind the next time you don't feel you can make it in to help your own team at the office.
But in the meantime, here are some athletes who came down with the flu -- and how that affected their job performance.
Michael Jordan and the Chicago Bulls won the title six times in eight years from 1991 to 1998, missing out only in the two seasons Jordan missed because of his brief retirement to play baseball.
No one was able to stop them -- apparently not even the flu.
With the Bulls leading the Utah Jazz three games to one in 1998, Jordan came down with the flu. But it wasn't enough to keep him off the court.
In the last two games of the series, Jordan played despite his illness.
He was able to score 45 points in Game 5, but Utah pulled out a narrow 83-81 victory.
But in Game 6, Jordan scored 38 points, finishing the game with a memorable shot to beat the buzzer and lift the Bulls to the crown.
The San Francisco 49ers won Super Bowl titles in 1988 and 1989 and were aiming for a three-peat in 1990.
The 49ers and the New York Giants started off their respective seasons with 10 straight wins, but each lost their next game, marring what would have been a match-up of the two teams with the best records in NFL history.
The 49ers pulled out a 7-3 win, so the teams seemed evenly matched when they met again for the right to represent the NFC in Super Bowl XXV.
But on Friday before the game, 49ers All-Pro quarterback Joe Montana missed practice with the flu.