New Zealand Davis Cup captain Alistair Hunt has chosen to use Michael Venus only for singles rubbers.
Former Wimbledon champion Marion Bartoli has sparked speculation of a return from retirement.
A selection headache involving the man set to succeed him awaits Australian Davis Cup captain.
Men's tennis "big four" might need to be a "big five" after Japan star edges past Briton in ATP rankings.
Former world No 4 Juan Martin Del Potro said he was confident of a full comeback "very soon".