The 44-year-old made over 100 appearances for the Serie A side during a four-year spell in the mid-1990s and has been strongly linked with a return to the club following Delio Rossi's departure.
On Thursday Mihajlovic insisted he was fully focused on his role with Serbia, but Karadzic expects the head coach to leave following their friendly with Russia on Friday.
"In a few days we will have a clearer picture of the situation," he told the Gazzetta dello Sport.
"I would like him to stay at the helm of our national team, but even if I have not spoken with Sampdoria president Edoardo Garrone, I am not very optimistic that Sinisa can stay with us."
Mihajlovic has been in charge of the national team since 2012, having previously managed three clubs in Serie A.
