Now that baseball seems to have acquired the stately rhythms of a pitchers' minuet, football has surely taken over as a circus sport complete with battered gladiators and spinesnapping action. The fabled offensive lineman of the Green Bay Packers, Mr. Kramer has, purportedly, kept a diary (at least twice a week) of the 1967 season. After a recital of the agonizing training, the enforced retreats, the Jovian abuse of Coach Vince Lombardi, Jerry ends the seasonal diary with an aria about the reason for it all: ""the guys. . . the shared excitement."" Since Kramer with his twenty-two operations, mainly due to field injuries is not atypical, one would guess that the other enormous gentlemen in pro football would agree to nothing less. Jerry's diary--about as ""inside"" as you can get--opens locker room doors to the not-quite-real world of Vince Lombardi where grown men hide ice cream cones behind their backs and the players kneel in the Lord's Prayer after creaming Oakland in the Super Bowl.