Town are reported to be in talks with released Sunderland central defender Matthew Kilgallon.
The 29-year-old, who has also played at left-back, started his career at Leeds, spending time on loan at West Ham while with the Whites.
In January 2007 York-born Kilgallon joined Sheffield United for an initial fee of £1.75 million, where he made 124 starts and two sub appearances, scoring twice, before moving to Sunderland on a Bosman in the summer of 2010.
The 6ft 2in tall defender made only 24 starts and two sub appearances in three years with the Black Cats, during which time he spent short spells on loan at Middlesbrough and Doncaster.
His release, along with that of former Blue Titus Bramble, was confirmed by Sunderland yesterday.
Blues boss Mick McCarthy looks set to add central defenders to his squad this summer as cover for first-choice pair Tommy Smith and Luke Chambers. However, given his experience, Kilgallon would seem more likely to be looking for a club where he will play more regularly.