Sir Rod Stewart has been urged to “take care of yourself” as fans have been left “praying” following his latest health blow. The 79-year-old admitted he was “absolutely gutted” to have to cancel an upcoming show after doctors diagnosed the rocker with strep throat. News of Stewart’s decision to axe the gig comes just days after he addressed his health concerns in a new interview, claiming to be at ease with the fact his “days are numbered”. While the Maggie May hitmaker has always insisted he has no desire to slow down and retire, his latest diagnosis has sparked concern over his touring futur…