Great Britain trail 2-1 in their Davis Cup World Group tie in Spain after Jamie Murray and Dominic Inglot were beaten in the doubles by Pablo Carreno Busta and Feliciano Lopez.
Murray and Inglot were second best throughout, losing 6-4 6-4 7-6 (7-4).
Britain must win both reverse singles rubbers on Sunday to be victorious in the tie on clay in Marbella.
Cameron Norrie and Liam Broady are due to play for GB but captain Leon Smith can select Kyle Edmund if he is fit.
The Australian Open semi-finalist was not chosen for Friday's singles because of a hip injury.