Qualities and Measurements

The ball is: 

• spherical 
• of a pressure equal to 0.6 – 1.1 atmosphere (600 – 1100 g/cm2) at sea level (8.5 lbs/sq in 15.6 lbs/sq in) 

Replacement of a Defective Ball

If the ball bursts or becomes defective during the course of a match: 

• the match is stopped 
• the match is restarted by dropping the replacement ball at the place where the first ball became defective 
• If the ball bursts or becomes defective whilst not in play at a kick-off, goal kick, corner kick, free kick, penalty kick or throw-in the match is restarted accordingly.

The ball may not be changed during the match without the authority of the referee.

Additional balls 

Additional balls may be placed around the field of play for use during a match provided that they meet the requirements of Law 2 and their use is under the control of the referee. 

Extra balls on the field of play 

If an extra ball enters the field of play during the match, the referee shall stop the match only if it interferes with play. Play shall be restarted by a dropped ball in the position where the match ball was at the time when the match was stopped. 

If an extra ball enters the field of play during the match without interfering with play, the referee shall have it removed at the earliest possible opportunity.