Alastair Cook has identified Hashim Amla as the main threat to England's chances of reaching the ICC Champions Trophy final.
Amla will open South Africa's innings alongside Colin Ingram in the first of the two semi-finals at The Oval on Wednesday.
The England skipper is all too aware of the right-hander's abilities, having watched him compile an unbeaten 311 during the tourists' victory in the first Test on the same ground last summer.
Amla failed to build on starts in the matches against India and the West Indies but he top scored with 81 to set up a 67-run victory over Pakistan in the Proteas' other Group B match.
"He's a massive player for them. He's a danger man and he's one of their key players," said Cook.
"We have to strike early, if he gets in he's a danger to us but if we can get him out that puts pressure on the other players in their set-up."
Cook also dismissed suggestions that his side were under increased pressure to perform in front of their own fans.
"It's whichever side handles the pressure well tomorrow. People in that side, in your own side, have to stand up and deliver and that's what you have to do," he said.
"We have amazing support at home. We're used to playing in front of these big crowds and we wouldn't swap the support we've had in this tournament or the support we have at home or abroad with anyone. I don't see it at all as a hindrance."
Cook also revealed England will not risk spin bowler Graeme Swann for the game if they are not 100 per cent sure of his fitness.
"We haven't ruled him out totally. We will have to see how he trains today and pulls up tomorrow," Cook said.
"There is one thing for certain - he won't be risked. Tredders (James Tredwell) is an exceptional bowler so we might be cautious with him and be sensible."