And Derby chairman Adam Pearson confirmed that a deal is now in place for the 28-year-old: "The two clubs have agreed a deal and we are reasonably happy with the package, so it is now down to Kenny to sort things out with Rangers.
"I don't envisage any problems because Kenny is keen to go to Rangers and Rangers are keen to sign him."
Pearson also revealed that the former Celtic forward was also on the shopping list of a number of other clubs.
"We have had one firm offer and three serious enquiries about signing him but Kenny told us he wasn't interested because he wants to go to Rangers."