Spain captain Sergi Bruguera said on Sunday that Rafael Nadal is “doing well” and wants to play at the inaugural Davis Cup Finals, despite his exertions at the ATP Finals this week.
Hosts Spain play their first tie against Russia in Madrid on Tuesday.
The 33-year-old Nadal was knocked out at the pool stage in London, but did secure the year-end world No 1 ranking ahead of Novak Djokovic.
Nadal was a fitness doubt for the season-ending event at the O2 Arena after pulling out of the Paris Masters with an abdominal injury, but managed to produce rousing comebacks in wins over Daniil Medvedev and Stefanos Tsitsipas.