Andy Roddick is due to arrive only next Tuesday to join the US team at the World Team Championships after being treated in New York for a back problem, dpa reported.
Tournament officials confirmed on Friday that the eight-nation show will go on without the drawcard as the event trials a new format at this edition.
Roddick hurt himself and quit after three games of a Rome semi- final last weekend against Swiss Stan Wawrinka. He then flew to the US for medical attention.
At the 31st edition of the Roland Garros warm-up, a tie - two singles matches and a doubles - between two nations will now be played over two days instead of one.
That means that every team will play on every day from Sunday's opening day through Friday, when round-robin competition ends. The final will be held on Saturday, a day before the Sunday start of the French Open.
On Sunday, Germany will meet Spain in a re-run of a Davis Cup quarter-final won by the visiting Iberians last month.
As at Davis Cup in Bremen, Philipp Kohlschreiber, injured at the Hamburg Masters but expected to be fit, and David Ferrer will face off in the opening match.
This week's Hamburg hero Nicolas Kiefer will take on Feliciano Lopez in the second rubber.
The doubles - possibly deciding - will be contested on Monday, giving spectators even more reason to return a day later.
In total, six singles rubbers will take place on Sunday, with two singles and four doubles on Monday.
In addition to Germany vs Spain, Russia will play Italy in the Blue Group on opening day. The US vs Czech Republic and Argentina vs Sweden are the scheduled ties in the Red Group.
The winners of these ties will then meet the losers on the second day of the round robins on Tuesday and Wednesday.
Red Group: USA, Argentina, Czech Republic, Sweden
Blue Group: Spain, Russia, Germany, Italy