Inter Milan have confirmed their interest in Cardiff's Gary Medel but have given up on Man City forward Stevan Jovetic.
Jeffrey Schlupp and Liam Moore have signed new deals with Premier League newcomers Leicester City.
The Rams are waiting to hear from City as to whether they are interested in a deal for the 28-year-old.
O'Connor has been made available for transfer by Derby boss Nigel Clough and he is in the final year of his contract at Pride Park.
O'Connor played under current Robins head coach Sean O'Driscoll at both Bournemouth and Doncaster.