Birmingham City's leading goalscorer has reportedly been informed that he can leave the club on a free transfer this month.
The 32-year-old is known to be a key member of Lee Clark's squad, but Birmingham currently have a number of financial problems that are likely to be eased if King is off the wage bill.
As a result, the Blues are open to the prospect of losing a player that has 18 months left on his contract for nothing, according to Sky Sports News.
With that in mind, Wigan Athletic, Norwich City, Cardiff City, Blackburn Rovers, Bolton Wanderers and Nottingham Forest are all said to be watching the situation with interest.
The report has also claimed the futures of Jack Butland, Nathan Redmond, Chris Burke and Nikola Zigic at Birmingham are uncertain.