Argentina's 2009 US Open champion Juan Martin del Potro and Spanish great Rafael Nadal will play each other in the first rubber of Sunday's play at the Davis Cup final it was confirmed.
Spain lead Argentina 2-1 going into the final day's play.
Under the tournament rules the captains of the teams have the option of being able to change the line-up an hour before the rubber starts but both opted to retain their original match-up.
Del Potro - who lost a marathon five setter to David Ferrer on Friday - is attempting not only to take the Davis Cup into the final and decisive rubber but also become only the second player to beat Nadal on clay in a best of five sets match.
Sweden's Robin Soderling is the only man to have achieved that at the 2009 French Open.
Del Potro has had one significant victory over his opponent - in the 2009 US Open semi-finals but that was on a hard court surface.
Should Nadal prevail in straight sets the final rubber - between Ferrer and either Juan Monaco or David Nalbandian - will not have to be played.