Jason Roy: England and Oval Invincibles batter backed by Kevin Pietersen

When you're out of form as a top-order batter in white-ball cricket it is hard to turn the tide... just ask Jason Roy.

The 32-year-old, who has played a huge role in transforming England's white-ball fortunes that culminated in winning the 2019 World Cup, has had a torrid summer so far.

Sunday saw his lean spell continue as he was caught at short fine leg for just 10 in Oval Invincibles' 39-run win at Welsh Fire in The Hundred.

It followed him getting out without scoring in their first game, off the first ball, and a run of 197 runs across 11 England games this summer.

However, despite his bad run of form he has received backing from former England international Kevin Pietersen and Invincibles captain and England batter Sam Billings.

"Jason is 32 years of age and what I'm sick and tired of in this country is writing people off at such a young age," Pietersen said on Sky Sports.

"Jason is a World Cup winner, he's done an unbelievable job for Eoin Morgan [England's former white-ball captain].

"He was told by Eoin, like the whole team, to go and smack the ball. With smacking the ball and being a risk-taker, you are going to fail and when you start failing, failing can happen for a long time.

"If Rob Key [director of England men's cricket] is listening, he is England's best player and he has been England's best player for a number of years. What they should be saying is 'back your best players'.

"If they replace him and put a new guy in for seven T20s in Pakistan and he fails, people start saying 'we need Roy for the World Cup'.

"Leave Roy. Give him the opportunity through the Hundred and T20s and back him.

"They've done it with Zak Crawley in the Test team - Ben Stokes has categorically said Zak Crawley will play for the rest of the season. England need to do that with Jason Roy in the T20 team."

• Follow live text, radio commentary and clips as Oval Invincibles visit Welsh Fire

Roy has built a reputation at the top of England's batting order as an intimidating presence, often bullying bowlers and scoring at a high rate, but this summer has seen him also use up balls.

His 76 runs in six Twenty20 internationals came off 98 balls - a strike-rate of 77.55 in comparison to a career 137.61 - while his 121 runs in five ODIs came off 186 balls, another format he has scored at more than a run-a-ball throughout this career.

Roy is under pressure with England having failed to win a series in a home summer for the first time since 2013 and a T20 World Cup taking place in Australia from mid-October.

However, Billings, who has played alongside Roy for England, said it is just "a matter of time" until Roy fires again.

"We have all watched and admired him all his career and seen what he can do to the best bowling attacks in the world," Billings told BBC Sport.

"It is funny. Everyone says go strike at 160, average 40 and take down the best bowler straight away and we take it for a given. Unfortunately this game is a game of peaks and troughs.

"It is just a matter of time with a player like that. He is a match winner and can solely take a game away from anyone."