Rafael Nadal and Roger Federer could go head to head in the first round of next year's Davis Cup after Spain were drawn to face Switzerland in the first round of the World Group on Wednesday.
The Czech Republic, who will meet Spain in this year's final of the team event, face Belgium while India, back in the elite 16-strong World Group for the first since 1998, have been handed a tough opener in Russia.
Argentina travel to Sweden while the United States have been drawn away to Serbia. Israel, beaten by Spain in the semi-finals last week, tackle Chile.
Federer recovered from his shock defeat against Argentina's Juan Martin del Potro in the US Open final to win both his singles in Switzerland's 3-2 defeat of Italy in a World Group playoff last weekend.
The 15-times grand slam champion has never faced Nadal in Davis Cup action and the prospect of facing the Mallorcan in Spain could persuade Federer to make himself available for the first round in March.
Neither he nor Nadal played in the first round tie between the nations in 2007 when Spain won 3-2.
"I truly enjoy playing for my country but I'll also have to see where I have my priorities for next season," Federer said after victory over Italy.
"Of course, there are the grand slams but there is also number one, which is a bit of a dilemma. Like in the other years, I will see after the Australian Open how I feel and if I play the first round."
Waiting in round two for the winners of the tie will be either Germany or France. The World Group first round is from March 5-7.