I'm not sure about the NFL part, but look at how well he ran in 2006:
In case you're short of time:
"... in 2006 set a world record of 10.72 seconds in the master's 100 meters for athletes aged 45 to 49 (Two years later, Gault set a new 200-meter world record of 21.80 seconds in the 45-49 age group)..."
That's crazy. He would have been just behind Denard's current time just a few years ago.