0705 GMT October 17, 2021
Nadal was included in a list of five Spanish players, with Roberto Bautista, Pablo Carreno, Feliciano Lopez and Marcel Granollers also picked by coach Sergi Bruguera, AFP reported.
A wrist injury forced Nadal to withdraw from the Shanghai Masters three weeks ago and it remains to be seen whether the 19-time Grand Slam champion is fit enough to play.
The Davis Cup starts on November 18 at the Caja Magica and Spain has been drawn alongside Russia and Croatia in Group B.
Controversial changes to the format of the 119-year-old tournament mean 18 teams will contest the finals over the course of a week.
Each tie will consist of two singles and one doubles match, with the winners of the six groups and two best-ranked runners-up progressing to the quarterfinals.
Andy Murray will represent Great Britain for the first time since 2016 after being named in the squad for next month's inaugural tournament.
Captain Leon Smith named Dan Evans, plus doubles pair Jamie Murray and Neal Skupski, in his initial team with a fifth player still to be decided, BBC Sport reported.
Kyle Edmund, who has lost his past seven tour matches, is not included.
Britain, who won the Davis Cup in 2015, face the Netherlands and Kazakhstan in the group stage on November 20 and 21.
"We are in a good position with improved strength and depth in our team and will be naming the fifth player in the next couple of weeks," Smith said.
"Dan is playing some of the best tennis of his career and firmly deserves his place back inside the world's top 50.
"It's been absolutely fantastic to see Andy back competing again, headlined by his incredible win in Antwerp.
"Jamie and Neal have been gaining much momentum as a team with impressive semifinal runs at Cincinnati, US Open, Beijing and Shanghai."
Britain was given a wildcard for the revamped event, which sees 18 nations compete across six groups in Madrid.