Over the course of a football season, there are a lot of knees that belong to defensive players. Why, just counting the starters, there are 22 a game. Over the course of a season, that adds up to 352.
And here is Doug Martin, with one normal-sized head.
In other words, yeah, this could happen again.
That's why this battle royale for the Bucs' backup running back is so important. Because if this offense loses Martin, as it did Friday against the Patriots, why, that would be the biggest kick in the head you could imagine.
Perhaps your heart hiccupped a bit Friday when Martin took a knee to the helmet that left him "dazed." In one year, Martin has established himself as a premier back in the NFL, and perhaps the MVP of the Bucs offense. There are a lot of touchdowns invested in Martin.
And yet, every now and then, someone else is going to have to carry the ball.
Maybe Mike James, the rookie.
Maybe Peyton Hillis, the veteran.
Maybe Brian Leonard, the guy from Rutgers.
Granted, last year, the backup running back for the Bucs didn't have a lot to do on Sunday afternoons. The Bucs handed the ball off to someone other than Martin only 97 times all season, the fewest times in the league for a team to not hand it to its No. 1 back.
Think about this: The Minnesota Vikings, with Adrian Peterson making a run for the most yardage in history, still left room for their other ballcarriers to rush 138 times. Houston, with Arian Foster rushing a league-leading 351 times, still had 157 carries for other players. Seventeen teams in the NFL had more than 200 carries by runners who weren't their starters.
Of course, part of Martin's heavy workload may have been a general dissatisfaction with then-backup LeGarrette Blount, who carried the ball only two more times than Josh Freeman scrambled with it.
This time, the backfield seems deeper. But just whom, and how many, the Bucs plan on keeping will be decided over the next two weeks.
So who is the favorite?
Is it Leonard, who played well enough in Week 1 that the Bucs didn't bother with him in Week 2? How much are you going to read into that?
"Brian did a great job in our opening game," coach Greg Schiano said. "He could have played Friday night, but we saw what we needed to see. He's an older guy, so it made sense to get the other backs all of the carries."
So is the job his?
"Definitely not," Leonard said. "We have two more preseason games to go. We're still battling for that second slot. May the best man win. We need the best back as a No. 2 to help this team win games."
Keep this in mind: Leonard is a key player on special teams, which is going to get some check marks in the argument to keep him. Odd, because Leonard didn't play on special teams in college or in his first two seasons in the league. In his rookie year, Leonard started seven games, so he was too valuable. Now, it is one of his loudest arguments to stay.
If not Leonard, how about James, this year's sixth-round draft pick?
James reminds a lot of people of Earnest Graham, and not only because he leads the Bucs in rushing this preseason. James so far has been steady, and he has shown a knack for keeping second and 8 from turning into third and 12.
"He's got good one-cut quickness," Schiano said. "He made a few guys miss in a phone booth. He's not a guy who will run away from you. He's not a burner. But as far as his jump cuts, when the tackle for loss is going to happen, he can keep it from happening."
Said James: "You never want to have any negative plays. I've been taught that since pee-wee football. I'm just trying to come here every day and get better and show the coaches that I want one of these jobs. And that I'm equipped to have one."
At 22, James is the youngest of the three main contenders for the backup job. He also plays on special teams. And keep this in mind, too. Teams love to keep their draft picks.
That leads us to Hillis, a 27-year-old former Browns star.
If you are judging by resume, Hillis is an easy choice. He has done more, and gained more yardage, that anyone else fighting for the backup spot. He looked more comfortable against New England, too, gaining 73 yards on 18 carries, which seems to indicate he's doing pretty well with the playbook.
"Peyton is just a big, strong downhill runner who is more athletic than people think he is," Schiano said.
Hillis, however, has a disadvantage in that he hasn't played special teams. When teams start crunching numbers for roster spots, that can hurt a guy.
"You know, I'm just taking it one day at a time," Hillis said. "I'm not going to think about things like that. I'm just going to do my best and see what happens."
Still, it's part of the rationale.
"It's not his strength," Schiano said. "That's not something he's done. It would be better if he had. That's part of the equation. What are the needs of our team? How many backs are you going to keep?"
The next couple of weeks will decide. Can the team keep four tailbacks? Only if it keeps fewer receivers and offensive linemen.
Eventually, one of them will be a back to compliment Martin. You know. "Good run, Doug." Also, "Nice cut, Doug."
Also, every now and then, he'll have to carry the ball.