Mackay, via the official website said today:
"Stephen is currently undergoing investigations for possible side-effects of his ongoing treatment for Sjögren's Syndrome.
“He received treatment for a stage One lymphoma and remains in remission while being dealt with by experts in the field.
"As a club we are fully behind Stephen as he bids to return to full training at the earliest opportunity.
“He is fit and well and is a part of what we are looking to achieve at Cardiff City."
So far McPhail has not featured in any of City's pre season games. We hope to see him back soon.