which is crazy to those of us who struggle to keep it off, but of course they're trying to keep mostly good weight. Many of them have to eat 8000 calories and work out 2-3 hours a day to keep the weight on, so when they stop playing they go down to 30-45 minutes of working out and a regular diet of 2000-3000 calories and the muscle falls off of them.
This is a particularly dramatic transition, so steroids are certainly possible, but this is something that happens to most BIG football players. It's sort of the reverse of what happens to WR/DB and NBA players, who tend to put on weight when they stop playing, because they've been working at staying as slim/strong as possible, instead of as big/strong as possible.