David Nalbandian will nurse a groin injury against Adrian Ungur in the opening match of the Davis Cup tie between Argentina and Romania on Friday.
Thursday's draw pitted Juan Monaco of Argentina against Victor Hanescu in the second singles.
The doubles on Saturday will see Argentine pair Juan Ignacio Chela and Eduardo Schwank against Hanescu and Horia Tecau. The reverse singles are on Sunday.
Argentina was a heavy favorite to reach the quarterfinals, but much will depend on Nalbandian's health. The injury forced him to withdraw from last week's Mexican Open, which followed a loss to Spain's Tommy Robredo in an ATP clay-court tournament two weeks ago in Buenos Aires.
"I'm fine and it's getting better every day," Nalbandian said at the draw.
"I feel pretty good and I hope I don't have to play on Sunday," he added, hinting he'd like the tie to be wrapped up in Saturday's doubles.
Ungur, unexpectedly chosen ahead of Victor Crivoi, was ranked 183rd, and made his Davis Cup debut only last year. This will be his first tie away from home.
Nalbandian suggested the thrill of playing in the Davis Cup might help him overcome the injury.
"Playing the Davis Cup is special and no match on the circuit gives you the same feeling," he said. "And playing at home adds to the motivation."
Nalbandian has won 10 of 11 singles in Argentina, and he's an impressive 20-5 in singles overall since his debut nine years ago.
Monaco, who will be playing in only his fourth tie spread over the last seven years, was relieved that Naldbandian will lead off the tie on outdoor clay at Parque Roca.
"The fact the tie opens with David let's me relax a bit," Monaco said. "It's likely we will be ahead and, perhaps, not need to worry about Sunday."
He and Hanescu are 1-1 in matchups, Hanescu winning their last encounter on Rome clay in May.
Romanian captain Andrei Pavel said Nalbandian's injury and the stress of playing before a home crowd might work in favor of his team.
"We know that Nalbandian has some physical problems, and that could be an advantage," Pavel said. "And the pressure will be solely on Argentina, not on us."
Argentina beat host Romania in their only previous tie in 1981.
Neither team has won the Davis Cup, both losing three finals - Argentina in 1981, 2006 and 2008, and Romania in 1969, '71 and '72.