Sky Sports understands a number of Charlton Athletic's Championship rivals are considering moves for defender Michael Morrison.
Morrison's contract at The Valley expires later this month and he could leave on a free transfer.
Charlton are desperate to keep hold of their star defender, but have yet to tie him down to a new deal.
That news has alerted several clubs to Morrison's possible availability, with the likes of Middlesbrough and Blackpool believed to be monitoring his situation.
The 26-year-old is regarded as one of the best defenders outside the Premier League, having made over 300 league appearances already in his career, and he is sure to have no shortage of offers if he moves on this summer.