Andy Murray will try to secure Great Britain's first Davis Cup final place in 37 years against Australia in Glasgow on Sunday.
Britain lead the best-of-five tie 2-1 heading into the final day, and need one win from the two remaining singles matches.
Murray is expected to face Bernard Tomic at 13:00 BST, although Australia could yet change their line-up.
Argentina lead Belgium 2-1 in the other semi-final in Brussels.
"To be 2-1 up going into the final day is very good but we've been here before," said GB captain Leon Smith. "There is an awful lot of work to get done.