Clark has been tasked with cutting the club's wage bill and King has been granted permission to discuss a move away from St Andrews'.
Speaking to the Birmingham Mail, Clark said: "Marlon's situation hasn't changed. He has been given a free, which was confirmed to him two or three days after the season had finished.
"He has been given time off to pursue other opportunities. He is talking to them with his agent, with my permission, and has been over the last couple of weeks, we expect a conclusion in the coming days."
It has been reported that at least three Championship clubs have expressed an interest in King as well as teams in other parts of Europe.
Birmingham start their Championship campaign at home to Watford on Saturday.