Singles players Juan Martin del Potro and Juan Monaco lead Argentina\'s attempt this weekend to earn a return to the Davis Cup finals. Del Potro and Monaco were given the singles assignments for the Argentines in a best-of-five semifinal series versus the Czech Republic. The series in Buenos Aires is to be played outdoors on a clay court. The Czech Republic-Argentina winner moves into the Nov. 16-18 finals against either Spain or the United States. Spain picked up its fifth Davis Cup title in 12 years when it beat Argentina in the 2011 finals. Del Porto, No. 8 in the world, is to open Friday for Argentina against the Czech Republic\'s Radek Stepanek, who is 3-1 lifetime against del Potro. The second singles match calls for Monaco, 11th in the world rankings, to take on sixth-ranked Tomas Berdych. Berdych is 5-0 in their face-to-face meetings. If individual experience is an indication, the edge goes to the Czech Republic as Berdych and Stepanek have 56 Davis Cup wins between them while del Porto and Stepanek total 18. Saturday\'s schedule has the Czech doubles team of Ivo Minar and Lukas Rosol playing Carlos Berlocq and Eduardo Schwank. The series turns to reverse singles Sunday with del Porto going against Berdych first followed by Monaco versus Stepanek. Argentina has never won the Davis Cup but has been second four times -- twice to Spain and once to Russia in the last seven competitions. Czechoslovakia won the Davis Cup in 1980 and was second in 1975. The Czech Republic lost in the 2009 finals to Spain.