Manager Mick McCarthy wants two new centre backs but faces competition for Johnson, who had an impressive season despite City's relegation.
Down and out: Birmingham were relegated to the Championship on Sunday
Derby are closing in on a deal for Kilmarnock midfielder Craig Bryson, 24.
There will be no fire sale. our stars will cost at least ?15m, vow BirminghamMcLeish to stay as Birmingham boss despite dropping out of Premier LeagueBirmingham City FC news, features and opinion