WHEN can a side have a substitute fielder? This question was put to me a few weeks ago.

The law says if the umpires are satisfied a nominated player has been injured or becomes ill since the nomination of players, the umpires can allow a substitute fielder or, if batting, a runner.

It is entirely up to the umpires to decide, not the opposition captain.

Obviously if there are other circumstances like a doctor on call, then the umpires can allow a substitute.

It’s nice to see some captains allow a substitute fielder for a player arriving late. They don’t have to, but in the spirit of the game, it’s good to see that happen.

What if it is known a player could be carrying an injury? Well, again, it’s up to the umpires to decide that something happened to worsen the injury.

Suddenly pulling up after bowling a few overs could constitute an injury had got worse.

Whatever happens, it’s entirely up to the umpires to decide to allow or disallow.

Remember very few umpires have medical training and will usually err on the side of caution.

The opposing captain has no choice in whether a substitute is allowed, who acts as a substitute or where he fields – but he cannot become the wicketkeeper. A substitute can’t captain the side, act as a runner for a batsman, nor can he bowl.

What about cramp? Can a batsman have a runner if he gets cramp?

Under ICC and county rules the answer is no. That is no longer classed as an injury, however as we play according to MCC law in the League, it is allowed and a batsman should be allowed a runner.

There is often confusion as to substitutes and replacements. A nominated player on the team sheet can be replaced by the captain with the consent of his opposing captain before the start of play, even if the toss has been made and the umpires have no say in this at all.

It could be that the player to be replaced has been injured between the toss and warm-up. It’s an agreement between the two captains. The player can take a full part in the game.

However substitutes and the allowance of, is made entirely by the umpires.