Billy Vunipola accepts that he must overcome his cultural instincts as well as South Africa's giant forwards if he is to impose himself on today's clash at Twickenham.
By his own admission Vunipola underperformed in last week's 24-21 defeat by New Zealand, and he was offered a combination of reassurance and harsh words by head coach Stuart Lancaster, who has demanded a reaction from his 22-year-old No 8.
Vunipola believes his inability to assert himself against the All Blacks is a result of his Polynesian heritage but is determined to throw off the shackles and carry the fight to the Springboks.
"I didn't enforce my normal game and felt I was quiet. It's tough because it's not in our culture to say 'look mum, I'm doing this'. As a kid you wait until you are spoken to," said Vunipola, whose dad and two uncles played for Tonga. "Sometimes I have got too much respect for older guys in the team, but I have to say 'give me the ball'.
"I need to impose myself with England like I do at Saracens and be who I am rather than tip-toeing round everyone. I have played the New Zealand game over two or three times in my head and there are times when I should have said to team-mates 'get out of the way, let me have a go'."
One of the complaints levelled at Vunipola is over a perceived inability to last 80 minutes for England with Ben Morgan usually stepping off the bench as the final quarter approaches.
Vunipola insists he is fit enough to finish a game and if he is axed for Samoa and Australia, then he will seek a divine explanation.
"I told Stuart I want to be the Lawrence Dallaglio of the team, the guy who never comes off, the go-to guy," Vunipola said.
"I never fear being dropped because I think my faith is my priority. God for me is No 1. Rugby is second.
"If I am dropped then maybe I am meant to be taught a lesson, maybe I am not being humble, maybe I am getting ahead of myself hence I played badly."
England - M Brown; A Watson, B Barritt, K Eastmond, J May; O Farrell, D Care; J Marler, D Hartley, D Wilson, D Attwood, C Lawes, T Wood, C Robshaw (capt), B Vunipola. Reps: R Webber, M Mullan, K Brookes, G Kruis, B Morgan, B Youngs, G Ford, M Yarde.
South Africa - W le Roux; J P Pietersen, J Serfontein, J de Villiers (capt), B Habana; P Lambie, C Reinach; T Mtawarira, A Strauss, J du Plessis, E Etzebeth, V Matfield, M Coetzee, S Burger, D Vermeulen. Reps: B du Plessis, T Nyakane, C Oosthuizen, B Botha, T Mohoje, F Hougaard, H Pollard, C Hendricks.
Ref - Steve Walsh (Australia).
England v South Africa,
Live, Sky Sports 1, 2.30