But the recalled lock says he is ready to face the World Cup cauldron if needed after answering an injury SOS from coach Michael Cheika.

The challenge in front of him is to replace Will Skelton's size 18 boots and throw his body around with as much influence as Skelton's 140-kilogram frame.

The Wallabies helped Carter get a short-term deal in France to keep the 26-year-old close by in case of injuries and he made the mad dash to London just four days before the huge battle against England.

It's a moment Carter thought may not come after he had knee surgery during the Super Rugby season and missed 12 weeks of action.

Most young Wallabies who choose to go to France are lured by a rich payday and change in lifestyle. But Carter's motivation at Bordeaux-Begles was to enhance his slim World Cup aspirations.

"I was actually in Bordeaux training just getting through the sessions there and trying to learn a bit of French," Carter said.

"It was pretty exciting actually. I obviously felt sorry for the guys who were ruled out injured.

"But I'm just keen to get back in and be a part of the squad.

"I basically got into Gatwick [Airport], got picked up, changed clothes, got strapped and did a couple of scrums."

Carter and hooker James Hanson have been called in to replace injured duo Wycliff Palu (hamstring) and Will Skelton (pectoral) in the 31-man squad.

Carter could be in action as early as Saturday (Sunday morning AEST) when the Wallabies play England at Twickenham.

But coach Michael Cheika must decide on the make-up of his line-up after hit outs against Fiji and Uruguay.

Sean McMahon is pushing for a spot on the bench to replace Skelton, while Carter and Ben McCalman have also pressed their claims.

Palu's international career is over after 57 Tests while Skelton could require surgery which threatens to force him out of the start to the NSW Waratahs' season.

Palu played through the pain of a torn hamstring in the 65-3 rout against Uruguay last weekend, but couldn't return to the field after half-time.

Carter is at the other end of his Test career, with 12 caps to his name, but he knows the pain of injury ruining a World Cup dream.

He fractured the tibia plate in his right knee and tore the medial ligament in a Super Rugby game for the ACT Brumbies.

His recovery time was three months but he raced the clock to be back in time to play 20 minutes against the USA Eagles earlier this month.

Carter, the son of former Wallaby David, didn't even have time to call family and friends before he was thrust into training.

Bordeaux-Begles were in the middle of pre-season training and Carter says that will ensure he hits the ground running if called on to play in front of 82,000 fans at Twickenham.

"I got in and they put me up in a hotel in Begles, which is where the training facilities are and they set me up with a car and introduced me to a few of the boys," Carter said.

"I got to see a bit of Bordeaux and then we started training, it was all go from there.

"[The Wallabies] gave me the option, they just said we can get you a short-term gig in Bordeaux for the duration of the World Cup and if anything happens you'll only be an hour away.

"I said if that's going to be the best thing for me then I want to be involved with that. Obviously it has worked out and here I am, ready to train."

Carter never gave up on his World Cup dream, despite being overlooked for the initial 31-man squad and fighting to overcome injury.

Carter hasn't played a Test since the loss to England at Twickenham in November last year. His knee injury forced him to miss the Super Rugby finals series and the Rugby Championships.