Ravichandran Ashwin says his 'Mankad' dismissal of Jos Buttler in the Indian Premier League (IPL) on Monday was not against the spirit of the game despite the run out sparking a chorus of disapproval from fellow players and pundits.

Rajasthan Royals batsman Buttler was run out on 69 while backing up at the non-striker's end, with Kings XI Punjab skipper Ashwin choosing to whip off the bails as the runner stepped out of the crease instead of completing his delivery to the batsman on strike.

The dismissal, named after India bowler Vinoo Mankad who ran out Australia's Bill Brown in similar fashion in 1947, is permitted under cricket's laws but viewed by some as going against the spirit of the game.

Buttler departed after an angry exchange with Ashwin and his exit condemned the Royals to a 14-run defeat in their IPL opener in Jaipur.

"On my part, it was very instinctive," Indian off-spinner Ashwin told a post-match news conference. "It wasn't planned or anything like that. It's there within the rules of the game.

"I don't understand where the spirit of the game comes (in). Naturally, if it's there in the rules it's there."

That view was not shared by Royals coach Paddy Upton.

"I think we'll leave it up to the IPL fans to decide if that's the kind of things they want to see, and we'll leave it up to the cricket world to judge R Ashwin's actions tonight," Upton said.

"But for us, we're certainly here to play cricket and entertain the fans and be good role models for people who love the game."

Former Australia spinner Shane Warne said Ashwin had committed a "low act".

"So disappointed in (Ashwin) as a captain and as a person," Warne wrote on Twitter. "(Ashwin) had no intention of delivering the ball ... this a not a good look for the IPL ... Why do such a disgraceful and low act like that tonight?"

England limited overs skipper Eoin Morgan said Ashwin had set a "terrible example" for young players, while former England skipper Michael Vaughan suggested the rules should be changed.

"If (Buttler) had been warned, well that's fine," Vaughan Tweeted. "If he hasn't and it's the first time, I think Ashwin is completely out of order ... I would prefer a one warning rule, then after that it's a free for all."