By Bipin Dani

The Sri Lankan team management had sought the match official's permission to allow Dinesh Chandimal, the reserved player, to keep wickets in place of Kusal Perera, who batted but was unfit to field in the last T-20I against South Africa on Tuesday.

Consent of the opposing captain (Keshav Maharaj in this case) was not required, according to Jonny Singer, the Laws of Cricket Advisor at the MCC.

He said, "Law 24.1 states: 24.1.1 The umpires shall allow a substitute fielder if they are satisfied that a fielder has been injured or become ill and that this occurred during the match, or 24.1.1.2 for any other wholly acceptable reason."

"If the umpires were satisfied that there had been such an injury (I believe a hamstring injury is being reported) then a substitute is permitted." 

Law 24.1.2 adds: "A substitute shall not bowl or act as captain but may act as wicket-keeper only with the consent of the umpires. The umpires appear to have given consent on this matter. In both cases, this is a decision for the umpires, not the opposing captain," Singer added. 

Tom Smith’s Cricket Umpiring and Scoring, MCC’s Official Interpretation of the Laws of Cricket, has the following to add on the subject:
“It is the umpires alone who decide whether a player can have a substitute or runner for whatever reason. The captains have no say. Once a substitute fielder is allowed, there can be no objection as to who it is or where he/she can field. If a wicket-keeper is injured, a captain may ask for the umpire’s consent for a substitute to keep wicket – this will be a decision for the umpires, and the umpires alone, to make. There is nothing to stop them saying yes, but they should not be swayed by the pleas, or complaints, of either captain".

There may, of course, be specific ICC Playing Conditions that supersede the Laws for this fixture.