Russia's Marat Safin has ruled himself out of the Davis Cup final with the USA and will not play again this season.
Safin was left exhausted after a Tibetan mountaineering expedition
Safin won the deciding rubber in last year's Davis Cup final and did the same when Russia beat France in the quarter-finals this year.
He has struggled for fitness and form this season and lost in the first round of this week's Madrid Masters.
"Marat decided there are four better players than him who are in form," a statement on his website read.
"Recently (Nikolay) Davydenko won Moscow again and (Dmitry) Tursunov won in Bangkok - both on hardcourts, the surface of the final."
The statement blamed Safin's recent struggles on exhaustion after a Tibetan mountaineering expedition.
"His mountain adventure - which he thoroughly enjoyed - took him out of his rhythm and also left him with no energy," read the statement.
"He will take some time off to get his energy levels back and then in three week's time will meet with his coach and they will spend a long period of practice time in Valencia - cleaning up his game and working hard on his approach, his work ethic and his general attitude to the year ahead."
The Davis Cup final takes place at the Memorial Coliseum in Portland, Oregon, from 30 November to 2 December.