Substitute

Firstly, the umpires must be satisfied that injury or illness has occurred to a member of the fielding side after the nomination of the players before allowing a substitute fielder. Also, the umpires have discretion to allow a substitute fielder, for other wholly acceptable reasons such as a doctor called-out to an emergency.

The captain of the batting team has no option but to accept the player chosen as a substitute by the fielding captain. When a substitute comes on to field instead of a nominated player, he is not compelled to field in the position vacated by the original player.

However, the substitute fielder is not allowed to keep wicket. If the reason for a substitute is the incapacity of the wicket-keeper, then one of the nominated players must take over this role. Except for the wicket-keeper, the fielding captain can place the substitute fielder in any position on the field. He can field at backward point even if he is a specialist in that position.

The substitute fielder is also prohibited from

acting as captain on the field. If it is the captain who is incapacitated, a deputy must act for him and the deputy must be one of the nominated players

bowling, even though he is acting as a substitute for a bowler

batting. He was allowed to join the side as a substitute fielder. When that team is batting he can take no part. Only nominated players can bat.

acting as a runner when his side are batting

The umpires should look out for sharp practice when a poorer fielder 'appears' to be injured and is replaced by a more youthful and active player.

Read more about Law 2 (Substitutes and runners,.......) at the MCC website