India had lost 1-4 to top-seeded Serbia in the first round to once again face the play-offs, while Japan scored a convincing 4-1 win over Uzbekistan to give themselves a chance to make the 16-nation World Group for the first time since 1985.
Back spasms has forced Paes to miss the flight to Tokyo and in his absence, the doubles rubber on the second day of the tie has now become a tricky affair.
Surprisingly, India have decided to field Somdev, instead of Rohan Bopanna, along with Mahesh Bhupathi in the doubles rubber against the home pair of Kei Nishikori and Go Soeda.
It means that 64th ranked Somdev will have to play on all three days, starting with the opening singles of the tie against 174th ranked Yuichi Sugita on Friday and then the reverse singles against Nishikori on Sunday.
Apparently, India's non-playing captain S P Misra wants Bopanna, another tremendous doubles player, to focus on just singles.
Bopanna has done extremely well in the singles in the Davis Cup and his real challenge will be against world number 55 Nishikori.
Somdev will start as favourite against Sugita and if Bopanna can turn the tables on Nishikori, India's job would become easy.
Nishikori is coming into the tie following a hip and back injury, which he suffered at the US Open.