1.Substitutes and Runners
(a) If the umpires are satisfied that a nominated player has been injured or become ill since the nomination of the players, they shall allow that player to have,
(i) a substitute acting for him in the field.
(ii) a runner when batting.
Any injury or illness that occurs at any time after the nomination of the players until the conclusion of the match shall be allowable, irrespective of whether play is in progress or not.
(b) The umpires shall have discretion to allow, for other wholly acceptable reasons, a substitute fielder or a runner to act for a nominated player, at the start of the match, or at any subsequent time.
(c) A player wishing to change his shirt, boots, etc. shall leave the field to do so. No substitute shall be allowed for him.