Filipe Luis, Willian, and Juan Cuadrado aren't with the Blues on their post-season tour, due to their participation in the Copa America. According to Jose Mourinho, that tournament will mean those three players won't be starting the seasonon time, as the Premier League kicks off earlier than usual this August:

'The players in the Copa America will obviously need a rest after that. So Willian, Cuadrado, and Filipe Luis will not start the season with us.'

The Blues aren't all that deep in the attacking band to begin with, so the absence of both Cuadrado and Willian will mean Chelsea start the season with one of Cesc Fabregas or Ramires in the attacking band, unless of course they add another option for Mourinho to select. The season (sort of) gets underway on August 2, when Chelsea take on Arsenal in the Community Shield, before the Premier League gets underway one week later.