South Africa coach Peter de Villiers has admitted his players are struggling to motivate themselves for Saturday's clash with England at Twickenham.

It is the last Test of the year for the Springboks, who have had a mediocre season since winning the World Cup, and De Villiers said some players' thoughts are already turning to their holidays.

Saturday's laboured 14-10 win over Scotland was the latest in a series of under-par performances by the Boks since being crowned world champions.

De Villiers said: "Sometimes it's very, very difficult to motivate yourself to stand up and just go on and on and on. It's always the biggest challenge to get motivated.

"Physically they're trained to deal with it but there's a mental fatigue that nobody sees. They're thinking 'five days more and then I can go back to my family'."

Another cause for concern for De Villiers is a forward line that has been hit by injuries to hooker Bismarck Du Plessis and prop Guthro Steenkamp.

Scrum-half Fourie Du Preez is already out with a thigh strain, while Bryan Habana and Brian Mujati both suffered knocks on Saturday but should be fit to face England.