The vector stencils library "American football positions" contains 38 symbols for drawing diagrams of American football positions.
"A football game is played between two teams of 11 players each. It is legal to have fewer players on the field, but playing with more on the field is punishable by a penalty. Teams may substitute any number of their players between downs; this "platoon" system replaced the original system, which featured limited substitution rules, and has resulted in teams utilizing specialized offensive, defensive and special teams squads.
Individual players in a football game must be designated with a uniform number between 1 and 99. NFL teams are required to number their players by a league-approved numbering system, and any exceptions must be approved by the Commissioner. NCAA and NFHS teams are "strongly advised" to number their offensive players according to a league-suggested numbering scheme." [American football. Wikipedia]
The symbols example "Design elements - Football positions" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Football solution from the Sport area of ConceptDraw Solution Park.