Lee Bowyer's move from Newcastle to Birmingham looks to have collapsed following protests by Blues fans.
Birmingham appeared close to completing a deal for the 28-year-old midfielder, but the move has hit a late hitch.
Owner David Sullivan told their website: "It looks like we are now going to lose out on a terrific player due to a small minority of fans.
"I am absolutely gutted. English midfielders with his ability are so hard to find."
Bowyer is expected to leave Newcastle this summer after he fought with team-mate Kieron Dyer during their game against Aston Villa in April.
The former England midfielder has had a troubled past but Sullivan felt he would have been a great signing for the club.
But a section of fans publicised their opposition to his signing through an online petition.
"Lee Bowyer would be a fantastic addition to our side," Sullivan added.
"We are looking to build the best squad that this club has ever had and the signing of Lee would take us a long way down that road.
"But the player has now said that he doesn't want to go to a club where he is not wanted.
"We are potentially going to lose out on a terrific player as a result of this petition and I can't describe how disappointed I feel at the moment."
The St Andrews club are yet to find a long-term replacement for controversial midfielder Robbie Savage who left the midlands to join Blackburn last season.
Sullivan revealed former Leeds star Bowyer was second only to last week's signing Mikael Forssell on manager Steve Bruce's wanted list.