Shaun Marsh will replace Clarke in Australia's second Test against India, which starts in Brisbane on Wednesday (local time)
The captain will miss the remainder of the four-Test series, having played no part in Saturday's thrilling final session at Adelaide Oval due to a right hamstring tear.
"The scans are not great ... the experts are looking at them and I can pretty confidently say that I won't take part in this Test series," Clarke said.
"I don't know exactly how long I'm going to be out for.
"There's certainly a chance, well there's a chance I may never play again.
"I hope that's not the case and I'll be doing everything in my power to get back out on the park, but I have to be realistic as well."
Clarke has suffered serious right and left hamstring injuries in the past four months, while his chronic back injury flared up on Tuesday.
"There's always that risk," Clarke replied, when asked if the latest setback could genuinely end the 33-year-old's glittering career.
"I did my left hamstring (three times in the past four months). I've done my right side of my back, I've just done my right hammy.
"I've got injury concerns at the moment.
"Now I've got to go back and do what the experts tell me, to give myself my best chance of being fully fit.
"But I think I have to be honest with myself and have a good hard think about things, definitely."
Clarke was passed fit to play the series opener, which Australia won by 48 runs, after overcoming a left hamstring strain suffered in a one-day match on November 14.
But the 33-year-old suffered a recurrence of his long-term back injury while batting on day one, which forced him to retire hurt.
Clarke had injections to soothe spasms in his back and returned to the crease the next day to complete a century.
"I have no regrets about playing this Test match. I have no regrets about going back on the field after I retired hurt," he said.
"I don't have one regret. This is the most important Test match of my career.
"Once you walk into the game, you have to do whatever it takes to finish that game."
Clarke was unable to do that, pinging his right hamstring while fielding a ball in India's second innings on Saturday.
He limped from the field accompanied by team physiotherapist Alex Kountouris, with scans confirming a serious setback.
Kountouris had described Clarke's back injury as "significant" on the morning of day two.
Clarke, who has managed three degenerative discs in his lower back since the age of 17, said it was "heartbreaking" to miss any game of cricket.
"Our first (World Cup) practice game is eight weeks away," he said.
"I'd love to take part in the tri-series, I'd love to take part in the World Cup but I just have to wait and see.
"Hopefully I'll get another opportunity to play again this summer."
