Manu Tuilagi runs the risk of never playing at another World Cup, according to Martin Johnson.
England's World Cup-winning captain admitted Leicester centre Tuilagi may never reach another global tournament after his six-month Test ban following conviction for assault.
Tuilagi was convicted of assaulting two female police officers in May and was immediately banned from England duty until January.
Johnson was England boss when Tuilagi jumped off a ferry into Auckland Harbour at the 2011 World Cup, and backed current head coach Stuart Lancaster's hard-line disciplinary stance.
"You never know do you?" said Johnson of Tuilagi's chances of featuring at future World Cups.
"Four years is a very long time.
"Four years as a player is almost unimaginable, because things change so much.
"You never know when your last game is in some ways.
"He's lost an opportunity at a World Cup. How many do you get? If you are very, very lucky then you get three.
"Who knows what the future might bring for him, but it's done now.
"So let's hope not, let's hope he's back and playing for England next year, but we'll see.
"If you let someone else in there, let's hope that person also takes their chance and plays very well too."
Lancaster's early World Cup preparations have been beset by disciplinary problems, the England boss choosing to drop Dylan Hartley after the hooker's latest ban.
Hartley was handed a four-match ban for head-butting Saracens hooker Jamie George in Northampton's Premiership semi-final in May.
The New Zealand-born front-rower was replaced by George in England's World Cup training squad and told he could no longer be trusted by Lancaster.
Fly-half Danny Cipriani is still waiting to hear whether he will face any charges over an alleged drink-drive incident, but has been retained in the England squad pending the outcome of that investigation.
Johnson's class of 2011 were beset by their own disciplinary issues, with Mike Tindall criticised for drinking in the build-up to matches, as well as Tuilagi's Auckland Harbour incident.
Johnson backed Lancaster's call to ditch both Tuilagi and Hartley - but also threw his weight behind the England boss' decision not to impose any curfews or alcohol bans.
"Those players have probably taken it out of Stuart's hands in many ways," said Johnson.
"The decisions have ended up quite straightforward.
"If guys don't learn their lessons then ultimately there have to be repercussions and those are the consequences.
"I don't know if they fully understand those consequences right now, but in time they will, when they look back on it.
"I totally agree with him not imposing any curfews or drink bans: if you're expected to make decisions and are trusted to make them on the field you've got to be the same off the field too.
"If you get to that point it's a pretty sad day."
England and Leicester's former talismanic captain recently met RFU chief executive Ian Ritchie to give his advice on World Cup preparations, and said he kept the message simple.
"It's pretty obvious, you've just got to keep yourself out of trouble as a squad," said Johnson, offering a stark anecdote to explain the scrutiny facing England.
"That's not just for World Cups, that's in general.
"Everyone has a camera, rightly or wrongly.
"I got filmed coming out of a filling station the other day, by a guy in a car.
"I said 'what are you doing? He said 'I'm filming you'.
"Why would you want to do that?"
Johnson was at Twickenham to unveil the Rugby World Cup 2015 ticket design.
World Cup-winning captains Johnson, John Eales, Francois Pienaar and Richie McCaw all feature on the range of ticket designs, with England's 2003 hero Jonny Wilkinson the image on tickets for the final.
Tickets will begin to be posted to fans from next week, with an interactive element provided by the Blippar App.
If supporters scan their ticket through the Blippar App on smart phones, their ticket will come to life through video footage of the specific captain featured on the design.
Tournament bosses confirmed that 85 per cent of all tickets for Rugby World Cup 2015 have now been sold.
"I didn't know my picture would be on some of the tickets," said Johnson.
"They've done a good job, they've taken good care of it, and the interactive element is quite cool as well.
"I'm not into tech for tech's sake, but when you do it you do think 'wow'.
"It's clever and well-thought out."