In both American and Canadian professional football, every player on the defensive team is considered eligible. The offensive team must have at least seven players lined up on the line of scrimmage. Of the players on the line of scrimmage, only the two players on the ends of the line of scrimmage are eligible receivers. The remaining players are in the
backfield (four in American football, five in Canadian football), including the
quarterback. These backfield players are also eligible receivers. In the
National Football League (NFL), a quarterback who takes his stance behind center as a T-formation quarterback is not eligible unless, before the ball is snapped, he legally moves to a position at least one yard behind the line of scrimmage or on the end of the line, and is stationary in that position for at least one second before the snap, but is nonetheless not counted toward the seven men required on the line of scrimmage. If, for example, eight men line up on the line of scrimmage, the team loses an eligible receiver. This can often happen when a
flanker or
slot receiver, who is supposed to line up behind the line of scrimmage, instead lines up on the line of scrimmage between the
offensive line and a
split end. In most cases where a pass is caught by an ineligible receiver, it is usually because the quarterback was under pressure and threw it to an
offensive lineman out of desperation. Eligible receivers must wear certain
uniform numbers, so that the
officials can more easily distinguish between eligible and ineligible receivers. In the NFL, running backs, wide receivers, and tight ends must wear numbers 0 to 49 and 80 to 89. Numbers 50 to 79 are reserved for linemen and are always ineligible on offense unless they report as eligible. In the CFL ineligible receivers must wear numbers 50 to 69; all other numbers (including 0 and 00) may be worn by eligible receivers. A player who is not wearing a number that corresponds to an eligible receiver is ineligible even if he lines up in an eligible position. However, a player who reports to the
referee that he intends to be eligible in the following play is allowed to line up and act as an eligible receiver. An example of this was a 1985 NFL game in which
William Perry, wearing number 72 and normally a defensive lineman, was made an eligible receiver on an offensive play, and successfully caught a touchdown pass attempt. A more recent example, and more commonly used, has been former
New England Patriots linebacker Mike Vrabel lining up as a
tight end in goal line situations. In the 2018 season,
George Fant has also lined up in the tight end position for the
Seattle Seahawks due to injuries to the starting tight ends
Ed Dickson and
Will Dissly. In the 2019 season the Atlanta Falcons declared
right tackle Ty Sambrailo eligible on many plays before throwing the ball to him for a 35-yard touchdown against the
Tampa Bay Buccaneers. Before the snap of the ball, in the American game, backfield players may only move parallel to the line of scrimmage, only one back may be in motion at any given time, and if forward motion has occurred, the back must be still for a full second before the snap. The receiver may be in motion laterally or away from the line of scrimmage at the snap. A breach of this rule results in a penalty for
illegal procedure (five yards). However, in the Canadian game, eligible receivers may move in any direction before the snap, any number may be in motion at any one time, and there is no need to be motionless before the snap. The rules on eligible receivers only apply to forward passes. Any player may legally catch a backwards or lateral pass. In the American game, once the play has started, eligible receivers can become ineligible depending on how the play develops. Any eligible receiver that goes out of bounds is no longer an eligible receiver and cannot receive a forward pass, unless that player re-establishes by taking three steps in bounds. Also, if a pass is touched by any defensive player or eligible offensive receiver (tipped by a defensive lineman, slips through a receiver's hands, etc.), every offensive player immediately becomes eligible. In the CFL all players become eligible receivers if a pass is touched by a member of the defensive team. A proposed rule change in the
XFL would make all players behind the line of scrimmage eligible receivers, regardless of position or number. ==High school==