Substitute, sub

A team is permitted to use a substitute fielder in place of a nominated player who has been injured or has become ill during the match. The umpires have discretion to allow a substitute for other, acceptable reasons. It might be that, by allowing a substitute for a player with a permanent disability, the game is enriched by a skilful batsman; perhaps a heavily pregnant cricketer will be able to play a few more games if a substitute fielder is permitted. It is up to the umpires to take account of all the circumstances and to use their discretion.
A substitute is not allowed to bat, bowl, act as wicket-keeper, a runner or as captain. Earlier versions of the Laws gave the captain of the batting side the right to specify positions in which a substitute may not field and also gave him the right to refuse to allow a substitute to be used at all. He no longer has those rights; the decision to allow a substitute rests solely with the umpires and a substitute is permitted to field in any position - other than wicket-keeper - even though he might be a specialist in that position.

A player is not allowed to have a substitute simply so that he can go off for a rest, or have a shower, a change of shirt etc, though some competitions do permit this. A fielder returning to, or coming on to the field of play after having had a substitute act for him may find he is not allowed to bowl immediately. If he has been off the field for 15 minutes or longer of playing time he cannot bowl until he has been back on the field for the same amount of playing time. There is no similar restriction on a batsman.

In order to add interest and to increase the range of tactical options available to sides, the concept of the super-sub has been tried. These are not substitutes as defined in the Laws of Cricket, but are replacements and are not subject to the same restrictions as substitutes are.

The term sub is used in the scorebook to record a catch taken by a substitute fielder.