Derby County have lodged a bid for Blackpool defender Shaun Barker, skysports.com understands.
The 26-year-old full-back, who can also play in the middle, has impressed hugely for The Seasiders this season.
The former Rotherham man has been tracked by a host of Championship clubs, who are ready to try and tempt Blackpool into selling.
East Midlands rivals Derby and Nottingham Forest were known to be leading the chase - as revealed by skysports.com last month - and now The Rams have followed up their initial interest by making a firm bid.
The bid is undisclosed and Derby are now awaiting Blackpool's reply with the hope they will be able to open talk with Barker - who has just one year left on his current deal at Bloomfield Road.