World number five Tomas Berdych will then take on Argentine Leonardo Mayer in the second of the opening day’s matches in Prague as the Czechs play in front of a home crowd for the first time this season.
Czech talisman Stepanek won the decisive match of the 2012 final against Spain to earn his country the Cup for the first time as an independent nation in Prague last November.
The 34-year-old, who had neck surgery in January, comes into the competition off the back of winning the men’s doubles title with Leander Paes at Flushing Meadows last weekend.
“Physically, I have no problem,” news website idnes.cz quoted Stepanek as saying. “Three days (of matches) have never been a problem. It won’t be a problem now.”
Argentina, runners-up to Spain in 2011, were beaten by the Czechs in Buenos Aires at the same stage last year and head into the semis without world number seven Juan Martin Del Potro.
For the second singles rubber, Argentine captain Martin Jaite has surprisingly turned to the lowest ranked player on the team, world number 93 Mayer.
“I had four good players and I believe that Leo will play great,” Jaite was reported as saying by news agency CTK.
For Saturday’s doubles match, Czechs Lukas Rosol and Jiri Vesely are pencilled in to face Carlos Berlocq and Horacio Zeballos.
However, the Czechs are likely to turn instead to Stepanek and Berdych, who played all key matches in last year’s title run.
“We are ready to play the role of favourites but nothing easy is expected,” Czech captain Jaroslav Navratil said.
The winners of the Prague tie will face either Canada or Serbia in the November 15-17 final.
The Czechs lifted the Cup last year for the first time since Czechoslovakia won in 1980.
Argentina have yet to win the Davis Cup despite four appearances in the final.
(Reporting by Jason Hovet; Editing by Alison Wildey)