Kevin Pietersen on retiring from cricket: 'I've had enough. Twenty overs fielding felt like a Test match'

Kevin Pietersen has revealed he decided to call time on his cricket career after realising he no longer had it in him to improve.

The 37-year-old announced his retirement at the weekend after deciding not to take part in the Pakistan Super League play-offs, ending a career in which he scored 23 centuries in 104 Test matches.

He walks away as England's second-highest run scorer of all-time across all three formats of the game despite being exiled from the national set-up following the divisive 2013/14 Ashes whitewash.

"I've had enough," Pietersen said on ITV's Good Morning Britain. "Twenty overs of fielding feels like playing a Test match so it's time to hang up the boots. I've got better and bigger things to go on to now.

"I've had a wonderful career but I just don't think I've got it in me to keep improving or try to improve."

While his on-field brilliance was clear, Pietersen emerged as a divisive figure in the England dressing room, culminating in an announcement from the England and Wales Cricket Board in February 2014 that, at 33, he would no longer be considered for selection.

Pietersen insisted he had no regrets.

"Being a South African in an English dressing room is occasionally frowned upon but I felt incredibly accepted and I loved my career," he said.

"I didn't mind pressing buttons to try and achieve really good things and to get the best out of people I had to press buttons they didn't like.

"Unfortunately or fortunately that's my character. I strive to be the best I can possibly be and help others be the best they can be and sometimes I rubbed them up the wrong way, I said things they were uncomfortable with.

"It is what it is. I had a pretty cool time doing my job and it really is one of the greatest things calling yourself a professional sportsman."

And Pietersen credited his England exile with turning him on to animal conservation - an area he now intends to focus on in retirement as part of the fight to save the rhino from extinction.

"I think I can do something better now than scoring runs for England," he said. "There's a huge issue in the world with trophy hunting...The England issue, yes, that was horrendous for a while but it allowed me to go back to Africa and rekindle my youth, rekindle my love affair with animals...

"It was a horrible time, of course it was. But it's water under the bridge, it's time to move on and I don't look back. I played 100 Test matches for England. If you'd asked me if I would even play first-class cricket or play at Lord's I would have said, 'Shut up'.

"For me it was the most incredible experience, a lucky experience, but now I've got a second chapter which is a lot more important than hitting a cricket ball."