England bowler James Anderson believes that he and his teammates will face their biggest challenge yet when they take on South Africa in a three-Test series.
The world's top Test side are in danger of losing their status as they prepare to go up against the likes of Dale Steyn, Vernon Philander and Morne Morkel.
"It's going to be a huge challenge," Anderson told Sky Sports News. "The last couple of times South Africa have been over here they've played really well and beaten us.
"Both attacks have shown in the last 18 months that we are strong units. I think it'll be a good battle. It's going to be really important that our bowling attack's on top form because their batting unit's really strong.
"We're looking forward to it, we like testing ourselves against the best in the world and there's four of their guys in the top 10 so it should be a good challenge. South Africa probably soak up pressure better than anybody else in the world so we might have to be more patient than we have in recent series, and that's going to be our biggest test."
The first Test gets underway on Thursday.