Zigic joined the Blues last summer from Spanish side Valencia, but the giant Serb has made it clear he does not want to play Championship football next season.
The 6ft 8in hit-man scored eight times in 34 appearances for the Blues, and should he depart would follow the likes of Roger Johnson, Craig Gardner and Sebastian Larsson out of St Andrews.
And agent Milan Calasan has claimed his client is attracting interest from the FA Cup winners, as well as Premier League rivals Tottenham Hotspur.
"Roberto Mancini admires Zigic and would love to see him at Manchester City. If Adebayor departs this summer, the transfer could happen,” Calasan told Serbian newspaper Blic.
"As for Redknapp, he is also heaping praise on Zigic, but he already has Crouch among his ranks."
Calasan admitted that Zigic does have interest from Germany but played down links with Nurnberg or Hannover.
"Much bigger clubs than those mentioned are in play, but it is not the right moment to reveal any names right now," he said.
"His career may well continue in a Bundesliga side."
While talk of a move to the Etihad Stadium outfit appears far-fetched, Calasan insists Zigic will definitely leave Birmingham and could be back in the Premier League next season.
He added: "A few English teams are showing interest in Zigic, but the obstacle now is his high wage at Birmingham.
"There has been interest from Everton, Wigan and Sunderland, but they cannot meet the quoted price.
"Zigic certainly won't be playing in the Championship. There are clubs in England which are willing to meet the demands for him, and it is possible he will be continuing his career in the Premier League."
