Jonny Wilkinson is braced for a punishing England tour to South Africa, admitting: ''We are going to be hauled out of our comfort zone.''

The Newcastle fly-half is among five World Cup winners who headed to Johannesburg last night.

But the severely-depleted squad also contains seven uncapped players, including six forwards, as England prepare for quickfire appointments with their pivotal World Cup opponents in Bloemfontein on May 26 and Pretoria a week later.

Saracens' back-row forward Ben Skirving underlined a rookie feel to England's pack resources by answering a late call yesterday as replacement for dislocated thumb victim Peter Buxton.

Buxton was injured during Gloucester's Guinness Premiership final drubbing against Leicester three days ago, and misses out on potentially his first and last England opportunity.

England last toured South Africa seven years ago, when they won in Bloemfontein - Wilkinson scored all 27 points - a week after losing narrowly at Loftus Versfeld, Pretoria.

It proved a significant trip towards the shaping of England's 2003 World Cup squad, but no serious comparison can be made this time around.

Head coach Brian Ashton opted not to select players from Leicester, Wasps or Bath, who all face European finals this weekend, while injuries have sidelined key personnel such as Mike Tindall, Mike Catt and Charlie Hodgson.

The combined effect places added expectancy on players like Wilkinson, whose own injury-plagued career means he has started just three England Tests since the 2003 World Cup final.

Wilkinson said: ''We are going to be hauled out of our comfort zone, but we want to go to South Africa and attack the tour and be positive.

''It is about sticking out our chests and being pro-active, rather than just hanging on in there.''

England's degree of difficulty is compounded by a miserable away record that has seen them register a solitary victory on the road - against Italy - in 15 months.

Only eight of an England squad captained by Jason Robinson have won 10 caps or more, suggesting the Springboks should encounter few problems securing a 2-0 series triumph prior to September's World Cup pool clash in Paris.