On-Deck Circle (1932)

“Even while Earl Combs, a dangerous lead-off batter, is up there swing [sic] and Joe Sewell, a tough man to strike out, is crouching in the ‘on-deck’ circle, the opposing pitcher can see the Babe casting his eye over his row of bats in the dugout.” Bob Dunbar, Boston Herald, September 30, 1932, p37

No earliest use given in Dickson Baseball Dictionary