The Rangers star is being tipped for a reunion with his former boss just months after arriving at Ibrox during Mark Warburton's reign.
Rangers' Niko Kranjcar in action
Kranjcar arrived at Ibrox on a two-year deal ahead of Rangers' return to the Scottish Premiership, but hasn't featured since November because of a knee injury.
The Gers have changed managers since then, hiring Pedro Caixinha to replace Mark Warburton - the man who brought Kranjcar to Ibrox.
And with the Croatian's former boss Harry Redknapp taking the reins at Birmingham on Tuesday, a move to St Andrew's is possible in the eyes of the bookies.
New Blues boss Harry Redknapp
Redknapp has signed Kranjcar at three different clubs, Portsmouth, Tottenham Hotspur and Queens Park Rangers, and the 32-year-old is sure to feature on his radar should he remain with Blues beyond the end of the campaign.
Caixinha will perhaps want to take a look at Kranjcar on his return to full fitness, however.
The former Dynamo Kiev playmaker has made 15 appearances for Rangers, scoring three goals and assisting another three.
Could Redknapp prise Kranjcar from Rangers this summer?