The Hollywood icon, 73, underwent a 30-day treatment programme for a dependency on prescription painkillers at a rehabilitation centre in Florida in August (09) after a nasty fall at his home in Hobe Sound.
His manager Erik Kritzer claimed Reynolds sought professional help after having painful surgery on his back.
He has since managed to stay off the prescription medication and has been trying to convince his former girlfriend Pam Seals he is a changed man.
But, according to the National Enquirer, Reynolds' attempts at a reconciliation have been snubbed and pals are concerned the setback in his love life will trigger a relapse.
A source tells the tabloid, "Even though Burt is sober now, Pam can't face going back to his mood swings and violent temper.
"I don't think Burt ever stopped loving Pam. Burt made calls to Pam and asked friends to speak to her for him. She always took such good care of him, and he wanted her back...
"Burt isn't good at taking rejection, and we're holding our breath hoping it won't push him over the edge."
The actor, who previously confessed to a reliance on sleeping pills, first dated Seals in 1993 after splitting from his then-wife Loni Anderson. They fell out in 2004 and sued each other amid claims of domestic violence, but they are said to have reconciled earlier this year (09) before breaking up again in the summer (09).