Toulon president Mourad Boudjellal said he will need to buy two players to replace Jonny Wilkinson if the England legend retires at the end of the season.
The 34-year-old World Cup winner surprised many by continuing this season but he has yet to make a decision on his future beyond the end of this campaign.
And Boudjellal said that replacing a player like Wilkinson is a task that rarely comes round.
"If his body says stop, Jonny will finish his career at the end of this season," explained the president.
"I think right now, he doesn't know. I asked him if we could talk about it but he told me he wasn't yet ready to discuss it. I respect that and I'll wait to see if he extends (his contract) or not.
"In any case, he's never told me: 'I want to finish my career'. Everything depends on the next six months.
"If he has an amazing six months and he feels good, I can't see why he would stop in June. However, if he feels he's played one match too many, he'll stop.
"Having to one day replace Jonny Wilkinson is the kind of thing that falls on you once in 100 years.
"We've made choices based on managing the game and reliability as a kicker because we will have to replace two players in one: a playmaker and a kicker with a 90 percent success rate like Jonny has.
"To find all that in one player is difficult, so we'll have to find it in two."
With France half-back Frederic Michalak and former Australia fly-half Matt Giteau also at the club, Toulon have other options at number 10 which allow them to rest Wilkinson and manage their use of the former Newcastle Falcons player.
Giteau will start at fly-half in Saturday's Heineken Cup clash with Exeter, with both Wilkinson and Michalak on the bench.
Even if Wilkinson does remain at the club, Boudjellal said a fly-half will be signed.
"As for Frederic Michalak's extension (he's also out of contract at the end of the season), we're in discussions. We want him to stay at RCT," added Boudjellal.
"But we'll increase competition at fly-half. We will sign a fly-half."