Decisive Point

There had been doubt over Nadal's participation after his exertions at Flushing Meadows, where he beat top-ranked Novak Djokovic to claim a second US Open title and his 13th grand slam singles crown.

He has not played in the Davis Cup since helping Spain to victory against Argentina in the 2011 final in Seville, their third triumph in four years and fifth overall.

View gallery."Spain's Nadal celebrates after defeating Ukraine's …

Spain's Rafael Nadal celebrates after defeating Ukraine's Sergiy Stakhovsky during their Davis Cup W …

After Friday's stroll against Stakhovsky, the French Open champion has now won 21 of his 22 Davis Cup singles matches, including a perfect 17 out of 17 on clay.

"We don't have it wrapped up yet, there is still one point to get and we have to be careful," Nadal said.

Spain are in the playoffs after losing away to Milos Raonic's Canada in the first round in February when Nadal, who had just returned from an injury layoff, did not feature.

Djokovic picked himself up after his US Open defeat to help Serbia move ahead against Canada in Friday's World Group semi-finals, while holders Czech Republic led Argentina 1-0.

In other World Group playoff matches, world number three Andy Murray beat 16-year-old Croatian Borna Coric 6-3 6-0 6-3 as Britain ended the opening day 1-1 in Umag.

Switzerland were unable to call on Roger Federer but took a 2-0 lead against Ecuador, with US Open semi-finalist Stanislas Wawrinka getting his side off to a winning start.

Germany also opened up a 2-0 lead against Brazil.