The Belgian lasted just eight months at The Valley and has been relieved of his duties after overseeing an eight-match winless run.
Curbishley has strong ties to the Addicks from a previous spell at the club, when he spent 15 seasons at the helm.
He guided them to the Premier League and to a seventh place finish in 2003/04, before walking away in 2006.
The ex-West Ham United boss admits he would be willing to discuss a potential return, but believes the Charlton board already have an alternative option in mind.
Curbishley told Sky Sports: “If they wanted to talk to me I’d have a chat to them. But I think they’ve probably got someone lined up. You don’t sack managers nowadays if you haven’t got someone lined up to go in.
“They are not the club I left. It’s been a long time now but they are still a big club.”
“You look at the Championship and you hear managers say ‘everyone can beat everyone else'. And if you get a decent run, and Charlton only need a couple of wins and they will be threatening the play-off positions again.”
Charlton have dropped to 14th in the second-tier standings, eight points clear of relegation danger and 10 adrift of the play-off places.
They have decided to act quickly in an effort to avoid being dragged into trouble, with there still 21 games remaining in which to piece together a push for a top-six finish.
Sky Bet have former Standard Liege manager Guy Luzon as the 1/4 favourite to inherit the reins, with Curbishley considered to be an outsider for the role at 16/1.