The Portugal defender injured his back in Saturday's 1-1 draw at home to Everton.
Portugal's doctor has examied Riccy and told him, that despite not having a serious injury, he needs rest and that rest should be about eight weeks.
Will Carvalho take heed of the advice and rest or will he be pressed back into club action quicker by Avran Grant?.
Chelsea have lost John Terry and Paulo Ferrieia to injury but Ashley Cole is close to a return to action and will figure for England against Austria on Friday. Terry has an outside hope of returning to action against Croatia on Wednesday.
Petr Cech could return to action on Saturday week against Derby County.