The top-ranked Nadal's bid to equal Bjorn Borg's record of six titles at the clay-court Grand Slam tournament will begin against John Isner, who is best known for winning the longest match in tennis history, 70-68 in the fifth set at Wimbledon last year.
Play begins on Sunday at the French Open, where Nadal is 38-1 and Isner is 2-2.
"Always unforgettable memories, no? Seriously, just to be back to this tournament is a really special feeling," Nadal said. "You remember a lot of things from the past years, so in general I feel a little bit like home."
Schiavone, the first Italian woman to win a Grand Slam tournament, is seeded fifth this year and will start off against Melanie Oudin. She lost her only match at Roland Garros last year in the first round.
Second-ranked Novak Djokovic, who has won all 37 matches he's played this season, will face Thiemo de Bakker of the Netherlands in the first round. Djokovic could face tests from 2010 U S Open champion Juan Martin del Potro of Argentina or big-serving Ivo Karlovic of Croatia in the third round, and then No. 13 Richard Gasquet of France or No. 23 Thomaz Bellucci of Brazil in the fourth.
Djokovic lost the first set against Bellucci before coming back to win their semifinal match at the Madrid Masters on clay this month.