Jos Buttler has admitted he is "not quite performing to the standards" he would like with the bat in Test cricket.

Butter is averaging just 23.14 since the start of the Ashes - a period of 14 innings in seven Tests - with one half-century (70 against Australia at The Oval). His average since he was recalled to the Test team in May 2018 is now 34.10, while his overall Test average, after 38 Tests, is 33. He has made just one century.

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Now Buttler concedes he is still "trying to work out" a way to play Test cricket with the natural aggression that has rendered him one of the world's most dangerous limited-overs batsmen. And he has resolved to be "a bit more positive" in the future if the situation allows.

"I feel like I'm not quite performing to the standards I need to," Buttler said. "I'm trying to improve that and affect games in positive ways for England.

"Since I've come back into Test cricket I've tried to trust my defence for longer periods of time. I've been able to do that on occasions. But [playing my natural game] is certainly something I'm trying to work out.

"You can do a lot of work in the nets but I'm spending a lot of time thinking about the game when I'm sat in my room or trying to visualise things or work through them in my head. Moving forward I've got to play the situation, but I will try to be a bit more positive."

"I want to look to be a bit busier and try to look a bit more on the positive side" Jos Buttler

He doesn't have to look too far for an example. For while Buttler made 12 off 39 balls in the first innings in Centurion, failing to marshal much resistance from the tail, his South Africa counterpart Quinton de Kock thumped 95 from 128 balls in the first innings and 34 from 37 in the second, to speed the game away from England.

"Quinton played a really good knock and put pressure back on the bowlers," Buttler said. "He tried to take the initiative and, watching that from behind the stumps, it resonated with me.

"When you're batting with the tail, you try to sum up situations and work out how best you can score. You work out your risk management.: what is too much risk; what is trying to push the game on.

"Looking ahead to this Test, I want to look to be a bit busier and try to look a bit more on the positive side."

While some have suggested Buttler would benefit from a position higher up the batting order to allow him time to build an innings, the England management believe that batting him at No. 7 allows him the freedom to play his familiar, aggressive game in the knowledge that he has limited before the lower-order are dismissed.

He has batted everywhere from No. 5 (eight times) to No. 8 (twice) since his return to the Test side (he has batted 13 times at No. 6 and 15 times at No. 7) with little obvious change in strike rate or average. Overall, he averages slightly more at No. 7 (33.15, with a strike-rate of 56.77) than No. 5 (28.62; strike-rate of 53.62) with No. 6 (average 39.69; strike-rate 63.15) his best position.

"It's obviously nicer to be 300 for 5 than 100 for 5," he said. "But you turn up and try to play the situation."

With Jonny Bairstow - who averaged just 18 in 2019 - also having lost form, there is not the pressure on Buttler's position from within the squad that there might be. But Ben Foakes, who averages 41.50 from his five Tests and is, in the eyes of many, the best wicketkeeper available to England, in the background, Buttler will know neither he or his team can afford a sustained fallow period.