Liam Dawson says he has found the step up to international cricket huge after a "frustrating" couple of Test matches against South Africa.
Hampshire all-rounder Dawson, 27, has taken just five wickets with his left-arm spin in the series so far.
"At international level, I'm still learning a hell of a lot," he said. "It's such a difference in standard compared to domestic cricket."
Dawson has been included in England's squad for the third Test at The Oval.
If selected on Thursday, it will be Dawson's fourth Test cap after making his debut in India in December. However, England may opt for an extra batsman - Middlesex's Dawid Malan - at Dawson's expense.
"From a personal point of view, (the past two Tests) have been hard work," Dawson told BBC Radio Solent. "I'm still learning a lot.
"I've found it tough and I haven't performed how I know I can for Hampshire, which is frustrating."
Dawson has experienced the high of a win at Lord's in the first Test against South Africa followed by the low of a comprehensive defeat at Trent Bridge in the second Test.
Batting at number eight, a pair at Lord's was followed by scores of just 13 and five not out at Trent Bridge, leading to scrutiny over Dawson's selection ahead of another top-order batsman.
"I've always thought looking from the outside, that media (scrutiny) is a massive part of international cricket," Dawson said.
"They're there to have their opinions. When you do well, everyone's a hero and when you don't do well, everyone's the worst player. But that's part of international sport and you just have to try to get on with it."
Interview by BBC Radio Solent's Andy Moon.