At first I thought he had a sudden illness.
Or the head band (with the Nike logo) caused some nasty allergic reaction with his skin.
Just before serving or receiving serve from the Argentinian player, Roger Federer religiously touches or seems to adjust his head band.
If we count it may total a few hundred times.
The match is still going on.
And then I realised why.
This guy is all about money $$$.
In pro tennis, they are paid millions to play matches.
They are not paid to play in the Olympics for their country.
Nike, the generous sponsor needs the hundreds of millions of TV viewers to be constantly reminded of their brand, by Roger Federer.