The umpires spoke to both teams to warn them not to throw the ball into the turf unnecessarily.

After he was dismissed, England batsman Jos Buttler took a close look at the ball on his way back to the pavilion.

"If I go into it I will say something that will get me into trouble," said Root. "I'm just going to leave it."

There are two white balls used in each innings of a one-day international, one for each end of the field.

Fielding teams will often throw the ball into the ground as much as they can to either soften it up so it becomes more difficult for a batsman to hit, or scuff up one side in the hope it will swing.

However, umpires will step in if they feel fielders are using the tactic excessively in a bid to alter the condition of the ball.

In both innings of Pakistan's 14-run win at Trent Bridge, the umpires stopped the match to warn captains Eoin Morgan and Sarfaraz Ahmed that their teams were making the ball bounce too much when it was thrown in by fielders.

Morgan explained: "The umpires came to me and seemed to think we were throwing the ball in on the bounce too much.

"They emphasised that it would be the same for both teams and it was relayed back to us during our innings that Pakistan were doing the exact same thing."

When Buttler was dismissed, the ball was rolled towards the umpire, across his path as he made his way back to the dressing room.

He picked it up and looked at it, then took a closer look before he threw it in the direction of the umpire.

"When the ball gets hit into the LED advertising boards, it does scuff it up quite a lot. I'm sure Jos was interested to see if one side was rougher than the other, if it looked natural or unnatural," said Morgan.

But former England captain Michael Vaughan believes that if either side did manage to alter the condition of the ball, it still gave the bowlers no assistance in a match that featured a total of 682 runs - the second-highest aggregate in World Cup history.

"There was nothing untoward, just a little bit of gamesmanship," Vaughan told BBC Radio 5 Live.

"It is a trick of the trade - you get the ball and you fling it one-bounce into the keeper. There were a few occasions today where the teams were throwing the ball in on the bounce from 10, 15 yards and that's where the umpires step in.

"England did the same so when the chase is on and the pressure is on, you can't start pointing the finger."