Dundee manager Paul Hartley has described forward Greg Stewart as 'impossible to replace'.
The 26-year-old, who is said to be on the radar of Championship side Birmingham City, has entered the final year of his current contract at Dens Park.
Hartley told BBC Sport: "I don't think we can replace Greg Stewart. Hopefully we can keep him for another year, but you never know.
"When you've got a player like that, you just enjoy him while you can. He is a pleasure to watch and a pleasure to work with also. He is a great lad, we're thankful we've got him.
"He's a player we want to keep, but we have to be realistic also. The player has ambitions."
The Scottish striker, who was on the shortlist for the PFA Scotland Player of the Year award last season, scored a double in the 7-0 Scottish League Cup thrashing of Forfar Athletic.
