Alex McLeish has urged Birmingham fans to focus on supporting their team rather than abusing former owners David Sullivan and David Gold when the pair return to St Andrew`s with current club West Ham.
The duo will return for the first time since selling up to Carson Yeung in a £81.5million deal last season.
Sections of Blues fans criticised Sullivan and Gold at the end of their reign for a lack of investment in the team.
McLeish is hoping the Blues fans will channel their efforts into making life uncomfortable for the West Ham players rather than Sullivan and Gold.
He said: "I would like the Birmingham fans to unnerve the opposition but more so the team on the pitch.
"The Birmingham fans have been renowned for their hostility over the years, not in a nasty way, but in making people feel uncomfortable on the pitch."