You could see the tell-tale signs of an FUE procedure in his hair when he appeared as a pundit on ITV during the European Football Championship.
You can see the red pin pricks in the front of his scalp where the donor hair has been transplanted.
That picture of Slaven in the pale blue shirt was taken at the beginning of June – almost certainly just a few days after he had had the procedure.
Flash forward to Saturday’s Match of the Day – four months later – and see how the former Croatia manager’s hair has improved in our second picture.
All the scarring has gone and his new transplanted hair has started to grow back. You can see that he has a much fuller covering of hair on top of his scalp.
He should be delighted with the work he has had because it has made a significant difference to his male pattern baldness.
There was speculation that 48-year-old Bilic had had an earlier procedure when he was managing Croatia during the 2012 European Football Championship in Poland and Ukraine.
He was wearning a wooly hat in the searing summer heat – suggesting he may have been covering up a procedure on his scalp.
Bilic would not be the first Premiership manager to have help with his hair. Liverpool boss Jurgen Klopp and the new Chelsea manager Antonio Conte have both bolstered their hair with transplants.
Here at Crown Clinic, our surgeon Asim Shahmalak is used to dealing with leading sportsmen. Earlier this year, the former Liverpool footballer and now successful TV pundit, Didi Hamann, showed off the positive effects of his FUE
transplant at Crown Clinic.
Dr Shahmalak often operates on sports stars who would rather not go public.
He said: “Image rights have never been more valuable for leading footballers. Clearly, these image rights are more valuable if you have a full head of hair.
“What leading international sports brand wants a bald man as their ambassador? Not many.
“It is why Wayne Rooney has been so proactive in addressing his male pattern baldness and why so many other footballers have followed his lead.”
As well as sports stars, we have treated lots of other celebrities at Crown Clinic including the model Calum Best and the TV doctor Christian Jessen, who had the most traditional FUT (follicular unit transplantation) form of transplant.