It has also been reported that ITF has confirmed that the Williams sisters had permission for the therapeutic use of banned drugs.
In his place, world number 26 Feliciano Lopez will take on 203 ranked Indian.
Fancy Bears', a Russian hackers group, has claimed that it has uncovered files which showed that several American athletes, including Venus and her younger sister Serena Williams were allowed to take banned substances by WADA under the TUEs procedure.
Sania and Rohan Bopanna had lost their mixed doubles semifinals in the Rio Olympics to American combo of Venus and Rajeev Ram, who ended up as silver medallists.
Spain, five-time Davis Cup champions, have been out of the World Group for the last couple of years.
In the reverse singles, it will be Saketh's turn to clash with Nadal, while Ramanathan will lock horns with Ferrer.
"It`s been the best year of my career so far and I hope I can keep it going," added Murray.
In its official statement regarding the cyber-attack on ADAMS, WADA announced on Tuesday night that Russia was behind the hacker attack on its database.
India will take on a full-strength Spain from September 16-18 in New Delhi.
Murray helped Britain to their first title since 1936 in Ghent in 2015 and is expected to play all three days on the hard surface at the Emirates Arena.
The 34-year-old though does not feel that his career would be any less if that elusive Major remains elusive.
Saketh Myneni could partner Leander Paes in the doubles match against Spain.
The original ruling had been expected by July 18, with Sharapova hoping a successful appeal would allow her to spearhead the Russian tennis team in Rio.
Her success in Rio was followed up by a final defeat in Cincinnati to Katerina Pliskova, who she then beat in the U.S. Open final.
Some of the recommendations (Lodha panel), I feel is too much. Let's not take anything away from the BCCI. They have looked after this game for 60-80 years.