The Scottish Premier League Club are in administration and have been forced to let their top earners go.
Burley was one of Warnock's transfer targets in the Summer and held talks with the Blades manager but a deal could not be met.
The Blades boss said: "Craig is a player who I was interested in a while ago, especially around transfer deadline days. I'm not planning anything but I'm always on the look-out for who might be available because you never know what might happen. We always like to stay on top of situations and part of that job is to be aware of what is going on."
In other news the Blades manager made his feelings known about the sale of Marlon Harewood from Nottingham Forest to West Ham United in a deal worth £500,000.
"We were very surprised when Jack Lester told us that Harewood was set to sign at that price - we were told that the figure would be more like two or three million," he told the club's official website.