27-year old attacking midfielder Shiels looks to have turned down a new contract offer from Kilmarnock whilst 34-year old central midfielder Kafes is a free agent after finishing with Greek club AEK Athens.
Rangers boss Ally McCoist has been in talks with the pair and has indicated that deals will likely be completed soon.
"It's not over the line yet but I know in both cases there is certainly a deal to be done there," he said.
"I've spoken to both players. They seem keen and we are very keen too so we'd be hopeful something could be done."