Neither player was named by the Swiss on Tuesday for their first-round clash with Belgium in Liege.
Federer and Wawrinka were the key players for Switzerland as they captured the famous trophy for the very first time last season, beating France in the final.
However, while both made schedule sacrifices in 2014, they are not prepared to do the same this year, although Wawrinka has not ruled out returning for ties later in the season.
Speaking at the ongoing Dubai Duty Free Championships. Federer said: “It wasn’t a difficult decision.
“I have played for so long, and I think by winning it I can finally do whatever I please, to be quite honest.
“It’s been a big burden for me throughout my career and one of the things that has caused more difficulties in my life than many other things, I must say.
“I always feel there is so much guilt put on you from the federation or from the ITF, more so than anybody else. So I’m happy I was able to finally tick that off and do it altogether.”
Swiss captain Severin Luthi has instead picked Yann Marti and Adrien Bossel, Henri Laaksonen and Michael Lammer, the latter being the only surviving member of November???s final-winning line-up.
Marti is the highest-ranked singles player at 294th in the ATP list but Luthi was putting on a brave face, saying: “These players have already shown that they can keep up with better classified competitors. We will prepare as always intensely on the games and try to seize the opportunities that present themselves to us.”
Belgium, led by David Goffin who has enjoyed a fine last six months on the ATP World Tour, will now start as heavy favourites to win the indoor hardcourt tie.
Meanwhile, Nick Kyrgios has been named in Australia???s team to face the Czech Republic in Ostrava despite recent back problems. Krygios is joined in new captain Wally Masur???s line-up by the in-form Bernard Tomic and Sam Groth.
Lleyton Hewitt completes the team for what could be his 39th and final Davis Cup tie. Twice a winner of the famous trophy with his country, the former world number one recently announced he plans to retire after next January???s Australian Open.
Tomas Berdych misses the tie for the Czechs who will instead look to Lukas Rosol and youngster Jiri Vesely to guide them to victory.
Kei Nishikori is one big name who will bve available. The world number five will lead Japan into their away tie with Canada.
The World Group first-round ties take place from March 6-8.