James Haskell has urged Danny Cipriani to chase a "once-in-a-lifetime opportunity" in France next season if excluded from England's Six Nations squad.
Haskell believes former Wasps team-mate Cipriani must not fall into the trap of "hanging on" too long in the hope of rekindling his England career.
Sale fly-half Cipriani is expected to be named in England's second-string Saxons squad on Wednesday, in a senior snub that could lead him to join Toulon in the summer.
Talisman centre Manu Tuilagi could miss the entire Six Nations with continued groin trouble, while George Ford, Owen Farrell and Stephen Myler are primed to be selected at fly-half ahead of Cipriani.
"I think the problem is you can be hanging on your entire life," former Stade Francais flanker Haskell told Press Association Sport of Cipriani's position.
"Sometimes your face doesn't fit, or there's too much competition around, and you need to make the right decision to suit yourself and suit your game.
"I don't regret one minute going to France, it was one of the best experiences of my life.
"If I thought it would have affected my England chances, because the rules were different then, then I probably wouldn't go.
"If I was on the fringe of the squad looking to play rugby and I had a once-in-a-lifetime opportunity to go and play in France, you've got to go and play in France, haven't you?
"I think that's what you've got to do.
"But everyone is different.
"Only he knows what the England coaches are saying to him, only he knows his own situation.
"But I respect anyone who broadens their horizons, Toby Flood chose to go to Toulouse.
"The worst thing you can do is get to 33 having hung on and still not really been involved, then gone over and miss the entire boat."
Haskell believes nine-cap Cipriani will face a difficult decision on whether to move across the channel in the summer if deemed England's fourth-choice fly-half.
England stick rigidly to the policy of not selecting overseas-based players unless in "exceptional circumstances".
"George (Ford) has been eased in and turned out to be outstanding," said Haskell.
"Danny's unlucky because there are some very good 10s about, I think he has been unlucky not to be involved as much and it must be frustrating for him - b ecause he would get into most teams or most squads, but England are blessed with some good backs.
"I've no doubt that if he keeps sticking with it he will keep knocking at that door because a couple of injuries and he's right in the mix.
"But I think certainly he has the skill-set, the attitude now and the ability to perform."
Exeter's Thomas Waldrom could step up to fill the void from Ben Morgan's leg break at number eight, while 36-year-old Nick Easter has been pressing for a recall with his form at Harlequins.
Haskell has settled at openside flanker at Wasps, but said he is ready to fill the number-eight breach as back-up to Billy Vunipola if required.
"I'd do it without thinking about it," he said.
"I've played what I think are some of my best games for England at eight.
"But you never know what's going to happen.
"I think there is enough cover in the squad to cope with the injuries.
"Steffon Armitage is interesting because everyone chats about him, but he's contracted abroad and knows the rules.
"Nick Easter's been playing well for a while and his addition to the squad if it happened would be a good one.
"But I think there are other number eights out there playing well who could slot in there.
"Essentially it's more about the balance of the back-row than the numbers on the shirts."