So if a guy has an appendectomy Wednesday, can he play football Sunday? What about the next Sunday? Might he be out the rest of the year?
Since the news broke that Chiefs quarterback Matt Cassel underwent an appendectomy this week, speculation has abounded about when he'll be able to return for the AFC West-leading Chiefs, who face division rival San Diego on Sunday. Reporters hurried to medical experts, fans made it a dominant topic around water coolers and on sports radio.
It seems like just about everybody who's ever performed an appendectomy, had an appendectomy, or knows someone who had an appendectomy, is weighing in.
Except the Chiefs.
Coach Todd Haley, who at first characterized Cassel's absence as "an illness," refused Thursday to say what his status might be.
"I appreciate the desire for all the Cassel questions that are probably out there," Haley said. "But I'm just going to keep it as I always do. He'll be listed as out today on the injury report, meaning he did not practice. Then we'll have his status tomorrow. I'll just leave it at that."
The most optimistic fans have Cassel trading his hospital gown for shoulder pads and starting against second-place San Diego. They're encouraged knowing Ben Roethlisberger missed only one game for the Steelers after an emergency appendectomy right before the 2006 season.
Pessimists are saying Cassel's gone for at least two weeks - road games at San Diego and St. Louis - and perhaps longer. Having to go with injury-prone backup Brodie Croyle - 0-9 as an NFL starter - has them fearing the ruin of what's been shaping up as Kansas City's best season since 2003.
Croyle hasn't taken one snap in a game all season and has not started a game since the 2009 season opener, when Cassel was hurt. But he is familiar with the system and is in many ways the same sort of quarterback.
"The good thing is I think there's a bunch of similarities," Haley said. "I think they can both be viewed as dropback quarterbacks. They both have enough mobility to get themselves out of trouble. Arm strength, those things, there's a lot of similarities between the two."
Haley said Croyle should still be prepared.
"It's our job to have each and every player ready to go," Haley said. "We constantly remind players you don't know when your number is going to be called. Before every game, we talk to our quarterbacks who aren't necessarily the starters about what are their favorite plays in the game plan, what do they like, so you'll have a game plan for each guy."
The Chiefs used a play clock in practice Thursday to help Croyle get accustomed to game speed.
"It's been a long time for Brodie. I think that's something a quarterback misses when he's not playing a bunch," Haley said. "We talked about our defense taking a great deal of pride this week, to really try to up the ante, so to speak, for the look the offenses get. They realize we're trying to get somebody game-ready who hasn't necessarily played a lot.
"If it is a situation where (Croyle) plays, I know the guys will kind of embrace that opportunity to help him have his best day."
No. 3 quarterback Tyler Palko was promoted from the practice squad Wednesday.