Kolkata Knight Riders spinner Varun Chakaravarthy said bowlers must learn to live with the Indian Premier League's (IPL) impact player rule instead of complaining about something they cannot change.

The rule, which was introduced to the tournament last season, allows teams to bring in one substitute at any time for a player in the starting 11.

The rule has been credited with helping produce some massive totals this season, with teams taking the shackles off their batsmen early in their innings knowing that they can bring in another batter if required.

"The impact player rule was there last year too but there weren't as many high scores," said Chakaravarthy, who bagged 3-16 in Monday's seven-wicket win over Delhi Capitals.

"The main thing is teams have understood better how to use an impact player this season. They all know that there is extra batting (available if needed) and charge from the first ball.

"That's how it's going. How much ever the bowlers cry, that's how it is. We have to take up the challenge. You can't change the size of the ground, you can't change anything," he told reporters.

Chakaravarthy took the wickets of Rishabh Pant, Tristan Stubbs and impact player Kumar Kushagra as Kolkata restricted Delhi to 153-9 in 20 overs.

A blistering 68 off 33 balls from Phil Salt at the top of the order ensured Kolkata got home with 21 balls remaining and stay on track to secure a playoff spot.

Kolkata are second in the standings with six wins from nine games and face five-times champions Mumbai Indians on Friday.