Smith could give reserve Alex Ward a chance in Sunday's two dead rubbers, which are reduced to bestofthreesets, but hinted he was likely to stick with James Ward and Baker.
With Britain now trailing Switzerland 3-0, the two reverse singles rubbers left to play on Sunday have been rendered meaningless, though the matches will go ahead although likely to be reduced to bestofthreesets.
Murray had played his best tennis of the year in beating Federer to win the Toronto Masters in August, and with a 7-5 career record in his favour he has repeatedly proved that the Swiss star's game is one he can counter over the bestofthreesets.