Spa and the next race at Italy's Monzacircuit are the two fastest on the calendar and should play to McLaren's strengths with a quicker car on the straights than the Red Bull.
Hamilton will continue to run with an aerodynamic package suited to Monza's low-downforce circuit, which includes a rear wing with a lower angle of attack - approximately 40 degrees compared to Button's conventional rear wing, which is raised at around 70 degrees.