Is there a minimum number of players needed on the field in the NFL?

Question

In the NFC Divisional playoff game on 2018-01-14 between Minnesota and New Orleans, Minnesota's Stephon Diggs scored a touchdown as time expired in the fourth quarter to take the lead and thus win the game. Of course, the game does not end till the PAT is attempted. The players, media, coaches, staff, and security rushed the field. After about ten minutes, the officials were able to get everyone off the field and the Minnesota offense on the field. The Saints were not there, and it took another minute or so to get eight Saints onto the field and onsides before the Vikings could snap and kneel-down.

Now, why did they need eight Saints there? Why not seven? One? Zero? At what point does "eh, it's your fault you didn't have enough players on the field" become "this isn't football"? What rule specifies the minimum number of players a defense must have in order for the ball to be declared ready for play?

Note this is not really a question of having enough players on hand, lest they risk a forfeit; let's assume the players are somewhere nearby (sideline or locker room) but just are busy with something else.

The only relevant rule, 5-1-1, doesn't address it.

The game is played by two teams of 11 players each. ... Penalty: For more than 11 players on the field of play or the end zone while the ball is in play: Loss of five yards from the previous spot.

Note: It is not a foul if a team has fewer than 11 players on the field of play or the end zone when a snap, free kick, or fair-catch kick is made.

Answer 1

It seems to be the case that the rules do not specify the minimum number of players on the defensive side in order to declare the ball ready for play.

Rule 3-2-2:

A Dead Ball is Ready for Play while the 40-second Play Clock is running when the ball is placed down by an official at the spot where the ball will next be put in play, or when the Referee signals for the 25-second Play Clock to start.

The rules go on to refer to a ball that is ready for play several more times, but in no case does it define what conditions must occur before the ball is to be made ready for play. The rules do refer to the "referee's signal" several times as a key part of making the ball ready for play. Thus I must conclude that the ball is ready for play whenever the referee signals it such.

In the NFC Divisional playoff game on 2018-01-14 between Minnesota and New Orleans, the referee didn't signal the ball ready for play till all eight Saints players that were running to get onside were onside.

In the 1998 "just give it to them" game between Buffalo and New England, similarly the final try of the game was not germane to the outcome, but this time, there were zero players on defense to oppose the Patriots in scoring a two-point conversion.

So, as an actual answer to the question, under Rule 15-1-3, in order for the ball to be declared ready for play, the offense and defense may or may not need have some number of players present in whatever number the referee decides:

The Referee’s decisions upon all matters not specifically placed under the jurisdiction of other officials by rule are final.

Also, for 2019 and later, the rule 4-8-2c was added so that the game can end without the PAT attempt taking place, thus making the particular scenario from the Minnesota-New Orleans game in the question no longer relevant. However, it still could be relevant in case the defense was preoccupied, or perhaps if they stayed off the filed protesting a perceived bad call, as the Bills did in 1998.

Answer 2

On the offensive side the rule book states the following regarding position of players at snap time in Rule 7 - Section 5:

ARTICLE 1. OFFENSIVE TEAM. The offensive team must be in compliance with the following at the snap:

(a) It must have seven or more players on the line (3-19)

(b) Eligible receivers must be on both ends of the line, and all of the players on the line between them must be ineligible receivers

(c) No player may be out of bounds

Note: Offensive linemen may lock

So the offense needs at least 7 players at the line of scrimmage. This is without counting a quarterback, as the rules (surprisingly) don't mention that the offence must have a quarterback at snap. The Rule 7 - Section 6 - Article 4 mentions that:

A snap is a backward pass. The snap must be received by a player who is not on the line at the snap, unless the ball first strikes the ground. If the ball first strikes the ground, or is muffed by an eligible backfield receiver, or quarterback under center, it can be recovered and advanced by any player.

Theoretically, the offense can snap without a QB, make sure it hits the ground and then any player can pick it up and run a play.

Thus we have that in theory the offense only needs 7 players for a play. But in practice, you'll never see the ball get snapped without having some under the center as you're almost guaranteed to lose possession of the ball with a player in the back field. Hence, in practice the minimum number pf players on the field on the offense would be 8.

For the defense and the special teams, there are no rules similar to the Rule 7 - Section 5 - Article 1 that specified the minimum number of players. There are rules that specify the maximum number of players you can have on each side of the ball at the snap time, but I didn't find any rules for the minimum number.

Note: I will continue looking for a limit on the defensive side and will update the post when I find an answer.

Edit: The Rule 5 - Section 1 - Article 1 of the NFL rule book states the following:

AT THE SNAP

If a team has more than 11 players on the field of play or the end zone when a snap, free kick, or fair-catch kick is made, the ball is in play, and it is a foul.

Penalty: For more than 11 players on the field of play or the end zone while the ball is in play: Loss of five yards from the previous spot.

Note: It is not a foul if a team has fewer than 11 players on the field of play or the end zone when a snap, free kick, or faircatch kick is made.

This rule mentions that on either side of the ball the teams can have at most 11 players legally. Any more results in a penalty while any less is fine, as long as other rules are not violated.

I have yet to find any reference to minimum number of players needed on the field on the defense. My guess for now is that there's no such limit.

Answer 3

NFL Rule 7-5-1a says

The offensive team must be in compliance with the following at the snap:

- It must have seven or more players on the line (3-19)

This does not answer your following questions:

• Is there a minimum number of players needed on the field in the NFL?
• What rule specifies the minimum number of players a defense ... must have in order for the ball to be declared ready for play?

But this indirectly answers:

• What rule specifies the minimum number of players a[n] ... offense ... must have in order for the ball to be declared ready for play?