There are times when coaches refer to a player simply by his jersey number. Or when it comes to a penalty, officials simply refer to players by their number. And when keeping tabs on stats, it's not the name on the back of the jersey that stands out, but rather the players number.
It's an identifying factor for players, where their number is sometimes as well known as their name in football.
So what does go into selecting that number, a number that players know they will be identified by in their career?
For some players, plenty of thought goes into it. For others, it's simply the number they are assigned by the team's equipment manager because it happens to be available.
A few players offered up their take on why they wear their number.
Le'Veon Bell – No. 34
The best photos of Running Back DeAngelo Williams from the 2015 season thus far.
"I grew up in Arkansas and growing up in Arkansas you have two college football teams," said Williams. "You have the Arkansas Razorbacks and the Texas Longhorns. Growing up Arkansas had Chrys Chukwuma and the Texas Longhorns had Ricky Williams. I fell in love with watching Ricky, his running style was unbelievable, he won the Heisman Trophy and he was the all-around, crazy good back. I modeled my game after him when I was in high school. That is why I wore No. 34, because he wore it.
"When I got to college my game didn't translate over to college the way it was in high school. In high school I was 185 pounds and I was doing the things he did in college. When I got to college, 185 pounds wasn't big. I tried to run a guy over, and after I woke up I decided that since one of my favorite tailbacks of all time, Barry Sanders, I would pattern my game after him. I took tidbits of Ricky Williams game and tidbits of Barry Sanders game to develop my own style."
Mike Mitchell – No. 23
The best photos of Safety Mike Mitchell from the 2015 season thus far.
"Growing up I had always worn No. 34. My brother had it, my dad wore it. When I went to the Carolina Panthers as a free agent, DeAngelo Williams had No. 34. I offered to buy it from him. He was just being a stickler, so I was like all right.
"I thought what number is cool that I want, so I went to No. 21. Then I get here with the Steelers, and I had such a great year in Carolina, I wanted to stick with the No. 21. I get here and Rob Golden has No. 21. I offered to buy it from him, and he is being a stickler and said he wasn't going to sell it.
"That is how I got No. 23. Now I love it and I won't have another number. I take pride in it, because it's mine. It represents me, everything I am about. I take a lot of pride in that No. 23."