"In October 1987, Butz famously checked himself out of the hospital to play in the Redskins' game against the New York Jets. Despite having dropped from 313 to 287 pounds due to the illness and feeling dizzy in the second half, Butz made a game-saving sack of Ken O'Brien to stop a Jets' drive late in the game and was awarded the game ball. After the game, he checked himself back into the hospital where he remained until the following Wednesday."
https://en.wikipedia.org/wiki/Dave_Butz
"He only missed four games in his entire 16-year career. Butz was among the largest players in the NFL when he played standing 6'8" and routinely weighing around 300 pounds."