Good lineup for the QF. In a normal year you'd assume the semi's would see Murray, Nadal, Del Potro and Nikishori but given injuries and lack of form who knows.
One suspects that Murray probably has his second gold but if Nadal or Del Potro can really turn it on then both i'd say are better than him peak on peak game.
For Del Potro and Nadal to be looking at Olympic medals again though must be incredibly pleasing and unexpected for them. Wets the wistle for the US Open too.