It's conceivable that might be Gehrig. Early on in his career, he batted sixth. Going by the theory that the on deck batter is signaling a base runner, nless Ruth was batting fifth, that could be Lou.
"Batting sixth, behind Ruth and Bob Meusel, Gehrig went 3-for-5 with a double in his first game at first base that season"
From:
http://sabr.org/bioproj/person/ccdffd4c
MANY paragraphs, down.