Former Alabama All-American Amari Cooper is wearing No. 18 in his first game with the Buffalo Bills on Sunday afternoon. On Sunday night, wide receiver Davante Adams will make his New York Jets debut in No. 17.

Both Pro Bowl pass-catchers were traded last week, with Cooper joining the Bills from the Cleveland Browns and Adams joining the Jets from the Las Vegas Raiders. But Adams was allowed to keep the number that he has worn throughout his NFL career, while Cooper will be in his fourth NFL number.

RELATED: AMARI COOPER ON TRADE: ‘IT DID REINVIGORATE ME’

Asked about his new number at his introductory press conference, Cooper indicated it had no special significance, but said he had a choice of only two numbers, which was true if the wide receiver wanted to keep a number in the single digits or teens. When Buffalo acquired Cooper, the only numbers from 0 through 19 not in use were 16 and 18.

Cooper wore No. 2 with the Browns. Kicker Tyler Bass wears No. 2 for the Bills. Players give up jersey numbers to new teammates who are more established in the NFL with regularity, sometimes in exchange for financial gratitude.

But Cooper couldn’t even have bought the number from Bass because NFL rules prohibit players from changing numbers during a season without changing teams.

“For competitive reasons, no player may change his uniform number once the regular season begins,” the rule reads. “Players on the practice squad that have not been on the active list for a regular-season game are permitted to change jersey numbers in order to make an approved number available for a new player on the active list. Special exceptions to this rule may be considered by the NFL Football Operations department depending on the circumstances (e.g., player traded to another team).”

No exemption was made for Cooper, just as there wasn’t one when he was traded from the Raiders to the Dallas Cowboys during the 2018 season. In that case, he switched from No. 89 to No. 19 because tight end Blake Jarwin already was in the 89 for the Cowboys.

The Bills have players in the 19 and 89 – wide receivers KJ Hamler and Jalen Virgil, respectively – but they are on the practice squad, so those digits were available under the rule if Cooper sought to work out a change.

The No. 9 that Cooper wore at Alabama is worn in Buffalo by safety Taylor Rapp.

The NFL did make an exception to its number rule for Adams.

When New York obtained Adams, rookie wide receiver Malachi Corley was in the No. 17 jersey. But Corley will be wearing No. 14 on Sunday night, with Adams set to be in the No. 17 jersey against the Pittsburgh Steelers on Sunday night.

Cooper had a choice of more than two jersey numbers after being traded. The NFL loosened a more rigid numbering system in 2021, so that wide receivers are permitted to wear any number from 0 through 49 and 80 through 89.

That’s why Cooper could switch his number to 2 when traded in the offseason in 2022. When Cooper entered the league in 2015, he could not continue wearing his Alabama No. 9 by NFL rules. At that time, wide receivers were restricted to the numbers from 10 through 19 and 80 through 89.

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Mark Inabinett is a sports reporter for Alabama Media Group. Follow him on Twitter at @AMarkG1.