The 31-year-old hitman has scored 9 goals in 43 appearances since joining Charlton in early 2008 and is the ideal man for the role Davey is targeting.
The Reds chief yesterday say he was after a target man and the 6'1" striker could prove to be the perfect man for the role.
Davey said yesterday:
"We are looking for a big striker, someone who can be a target man,"
"We've got Daniel Bogdanovic who is a finisher, Iain Hume who is a finisher and is sharp and good around his feet,"
"Jon Macken acts as a target man but isn't the biggest and is really a link man, so we need a big striker who can link the other three strikers."
Gray's Wikipedia article can be found here.