Lmcginlay has supplied a verifiable example from 1875.
OED researchers have traced the history of header in the football (soccer) sense of ‘a shot, pass, or clearance made by heading the ball’ back to 1891. It appears in the caption to an illustration of a player heading the ball in an annual publication of the Scottish Football League:
1891 ‘Gush’ Heads & Tales 32 (caption), Header.
However, we know from our research that the verbal use of head to describe the action (‘heading the ball’) goes back to at least 1871; with your help, we would like to see if an example of header in the football sense from before 1891 can be found.
Posted by OED_Editor on 15 October 2012 9.00