Saracens are resigned to losing Will Skelton during the World Cup in a development that would most likely result in his eventual departure from Allianz Park.

Skelton has enjoyed a stellar season after shedding over three stones and the giant Australia lock is now a regular in the European champions' starting XV, resulting in the offer of a new two-year contract.

His form has caught the attention of the Wallabies, who are unable to pick him in their World Cup squad because his total of 18 caps falls well below the minimum level of 60 appearances required for the selection of overseas-based players.

Exeter's Nic White is in a similar position, but by agreeing to join an Australian Super Rugby side in 2020, he has become available for Japan 2019.

"Will has spoken to me about it," Saracens director of rugby Mark McCall said of the club's players' player of the year award winner.

"He is keen to play in the World Cup, but he is also keen to play for Saracens, which is quite complex.

"There hasn't been much contact from Australia but I think there will be and we want our players to play in the World Cup.

"For that to happen he probably has to sign longer term there, which is not what we want but if that is what Will decides, that is what he decides.

"Nic White has some arrangement. We haven't been approached yet, but you'd imagine that might suggest something like that."

Skelton has flourished to the point that Maro Itoje has been shifted to blindside flanker to accommodate him.

England talisman Itoje admires his team-mate but insists that should he appear at the World Cup, friendship will be cast aside.

"When I see him play and I see him carrying and I see him hit people, I am happy he is on my side rather than the opposition," Itoje said.

"I've played against him before and that was when he wasn't in this type of shape. Even then he was a big deal to deal with. Now he has had a huge impact on the whole squad.

"He is in great form, he is truly in great form. But if he is playing for the Wallabies, unfortunately he will have to get chopped down like the rest of them."