TEMPE, Ariz. -- One of the first things inside linebacker Haason Reddick did upon arriving in Arizona the day after the Cardinals drafted him 13th overall this year was to pick a uniform number.
As with so many young players before him, it was a defining moment. The numbers on their backs have come to represent football players as much as anything on the field.
Unlike their counterparts in baseball or basketball, the large majority of football players don't have the benefit of being recognized by face because they're typically hidden from the public. Only a select few out of the nearly 1,700 NFL players -- including the Cardinals' Larry Fitzgerald -- can be recognized without their jersey, so numbers have become their most important identifying mark.
When it was Reddick's time to choose a number, he had one request. The digits had to equal seven, his number at Temple University.
Reddick was awarded No. 7 during his senior year, earning one of nine single-digit jerseys awarded by a vote of coaches and teammates because of his leadership and hard work.
"That was probably one of my biggest accomplishments there," Reddick told ESPN. "Just shows that you worked hard, you're a leader, you lead by example, you do things the right way. It's a tradition that's been around Temple for years."
Reddick had two options with the Cardinals that fulfilled his need: 52 or 43. No. 52 was taken by linebacker Zaviar Gooden. So No. 43 it was.
"That way I always keep that '7' with me," he said.
Throughout the Cardinals' locker room, seemingly every player has a story about why he wears a certain number. Some are meaningful, like wide receiver John Brown's. Some, like right tackle D.J. Humphries', aren't.
Brown's No. 12 didn’t start out with any significance. With the popularity of numbers between 10 and 19 increasing for receivers since Fitzgerald donned No. 11 in 2004, Brown only had a few options when he arrived in Arizona in 2014. So he picked No. 12. At the time, it was just a number. Then a family member wrote Brown a letter telling him that the No. 12 represents Brown's late brother, James Walker, who was killed in 2011.
"It's basically like we have an extra man on the field," Brown said. "He's guiding me all the time through everything, so that's why it means a lot to me."
When Humphries was drafted in 2015, he wanted either 70 (his number in college) or 75 (his number in high school). Both were taken, so he went with No. 74. He never thought about switching when either came available.
"No," he said. "I'm 74 now. I'm in it now."
Fitzgerald was given the opportunity to switch his number after his rookie training camp but chose to stay with his now-iconic No. 11.
That No. 11 was hanging in his locker when he reported for his first practice as a rookie in 2004. To this day, he doesn't know why it was 11, but his guess is that the equipment staff must have thought since it was closest to the No. 1 he wore at the University of Pittsburgh, he'd want that. And since 2004 was the first year the NFL allowed receivers to wear Nos. 10-19, Fitzgerald decided to keep No. 11 when former Cardinals coach Dennis Green asked if he wanted to switch to the more traditional receiver number of 80.
Fitzgerald doesn't know if he's single-handedly responsible for the influx of receivers wearing low numbers, but he thinks it's "really cool" to see the likes of Atlanta's Julio Jones wearing No. 11 and the New York Giants' Odell Beckham Jr. wearing No. 13 because Fitzgerald's class was the first to wear the low numbers.
As Fitzgerald influenced the receivers who came after him, Deion Sanders had that same kind of impact on one Cardinals cornerback.
Sometimes an NFL player gets to live out a childhood dream by wearing the number of their football idol. That's what happened to cornerback Patrick Peterson.
Sanders, a Hall of Fame cornerback, was Peterson's favorite player growing up, so when Peterson entered the NFL in 2011, he could no longer wear No. 7, the number he wore in high school and at LSU because it was his father's number. He went with "Prime Time's" number.
But, to Peterson, wearing No. 21 was more than just sharing the same digits as his idol.
"Watching him transcend the game the way he did, that's what I wanted to do when I got to the NFL being a punt returner, kick returner; being a lockdown, shutdown cornerback like he always talked about," Peterson said. "I'm a guy that you have to worry about for four downs -- first through third [on defense] and then, next thing you know, I go back on punt return and you have to worry about me again.
"To be able to be in the same breath as him and being able to represent his number the way I am, is definitely, truly an honor."
Then there are the times when a rookie enters the league looking -- hoping -- to wear his college number, only to find it hanging in a veteran's locker. That happened to both quarterback Carson Palmer and defensive end Frostee Rucker, college teammates at USC, when they were drafted by the Cincinnati Bengals three years apart.
Palmer wore No. 3 in college, but when he was drafted first overall by the Bengals in 2003, their incumbent starting quarterback Jon Kitna had that number and wanted the rookie to buy it from him. But Palmer didn't think No. 3, which he had worn since high school, was all that important, so he settled on No. 9.
"It's never been something I can't live without," Palmer said.
Palmer isn't superstitious enough where not wearing a certain number would have an impact on his play.
"I didn't feel like there'd be a jinx or anything like that," he said.
He was able to switch back to No. 3 with the Oakland Raiders in 2011 and kept it when he was traded to the Cardinals in 2013.
Rucker, however, hasn't been so lucky.
He wore No. 90 in college, but Justin Smith wore it in Cincinnati, so Rucker was given No. 92, which he wore for five years in Cincinnati and one year in Cleveland.
"There was no way I was going to have that talk with him because of who he was," Rucker said of Smith.
When Rucker signed with the Cardinals as a free agent in 2013, nose tackle Dan Williams was No. 92, so Rucker took No. 98. When Williams left Arizona as a free agent in 2015, Rucker grabbed No. 92.
"It's something that kind of sticks with you because we're not like NBA players where our helmets are off," Rucker said. "People recognize us by our football numbers unless we're certain people like Larry.
"I'm not at the point where the number defines me enough where I'm going to pay you to use this number. As well as it does define you, it's just a number."
Paying for a number wasn't above outside linebacker Chandler Jones when he was traded to Arizona in 2016.
Jones wore No. 95 for his first four seasons with the New England Patriots. It was given to him in the locker room after he was drafted in 2012, but he developed an affinity for the digits. When he joined the Cardinals, he found out that was defensive tackle Rodney Gunter's number.
So Jones tried to buy it from Gunter, although Jones didn't want to get into specifics of the amount he offered.
"It was a lot of money," Jones said. "Let's say he could've put his kids through college with the amount of money I offered him.
"I guess he wanted more."
Gunter didn't want more. He had worn No. 95 since his freshman year at Delaware State and, to him, the number represented years of hard work.
"I had pride and dignity in that number, so I didn't just want to give it up," he said. "I put in so much hard work in that number."
Gunter thought Jones was playing mind games at first when Jones made his initial offer. Gunter held firm and didn't give it up. But that's not to say he wasn't tempted.
"I was kind of like, 'Oh, man, that's a lot of money, especially since it's tax-free,'" Gunter said. "At the same time, it's pride, and my enjoying that number wouldn't allow me to give it up that easily."
There are about as many reasons why Cardinals players wear the numbers they do as there are, well, numbers in the locker room. Pride, tradition, connection, desire and emotion all come into play.
The numbers on their back do more than simply identify players. In a large sense, the numbers have come to define the players.