"There they go around Gravelle again," says Frank Gifford on ABC-TV's Monday Night Football from RFK Stadium.

"He may take another fine and go home again," comments Howard cosell.

"They" are the Redskins pass rushers, particularly Coy Bacon on his way around a Gaint offensive tackle to sack Joe Pisarcik.

"Gravelle" is not Gordon Gravelle, but New York tackle Gus Coppens. "Another fine" harks back the $15,300 assessed Gravelle by the Giants for reporting six weeks late.

It's all there on the tape, the network says of its telecast, but is the bit of repartee two minutes from the end of the game -- plus a game-long case of mistaken identity -- grounds for Gravelle suing Cosell for slander?

Gravelle thinks it is -- says he is considering just that. Meantime, the football player blasts Cosell in Cosellian terminology. " . . . a pompous, senile idiot. A disgrace to the broadcasting profession, the epitome of an arrogant egotist.'"

All this because of a press-box snafu in which an ABC spotter was told that Gravelle, in his first game since his temporary retirement, would be wearing No. 78. Actually, 78 was Coppens; Gravelle wore No. 71. Coppens was beaten numerous times by the Redskins during the game; Gravelle took the rap . . .