Martinez however is confident that the deal can go ahead, he said: "The medicals are very intense these days because everyone wants to be extra careful. We are no different and want to make sure we do things right.
"It can sometimes be part of the genes and the way you are. Players' hearts can be different sometimes."
Diame is no stranger to health complications and had to take a brief break from football whilst playing with Lens in France. He later returned with Spanish lower league side Linares and then Vallecano.
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