Johnson perviously wore number No. 28 in Tennessee, but it is unavailable in New York as that number was retired for Curtis Martin. Johnson settled on number 21, although that jersey technically wasn't available, either.
No. 21 was worn by Ellis Lankster, but swaying the cornerback to trade up his number wasn't too hard for Johnson -- nothing a little money couldn't solve. Lankster confirmed on Twitter that Johnson had paid him for it, but would not say how much.
As for Lankster, he'll now be sporting No. 31, previously worn by Antonio Cromartie.