Madrid - Russian star Daniil Medvedev pulled out of the inaugural Davis Cup Finals, which start on Monday, due to exhaustion, his captain Shamil Tarpischev said on Sunday.
The world No 4 lost all three of his matches at this week's ATP Finals in London, including blowing a 5-1 deciding-set lead and missing a match point against Rafael Nadal.
Tarpischev said Medvedev told him after his defeat by Alexander Zverev on Friday that he would not make the trip to Madrid.
"I knew right after his match against Zverev," said Tarpischev. "We talked about it a lot but I asked him not to rush into a decision and to talk about it the next day.
"He told me he was running on empty. He told me that he was ready to help the team, but that in his condition he was no better than the other members of the team and asked not to come."
Medvedev's withdrawal leaves Russia with only three players for the tournament - 17th-ranked Karen Khachanov, in-form Andrey Rublev and Evgeny Donskoy.
"The absence of Daniil Medvedev of course makes it more difficult for us, because I have fewer options," added Tarpischev.
"But I still think we have a good team and we will fight."
The 23-year-old Medvedev had a gruelling run towards the end of the ATP season after reaching six consecutive finals.
Russia play the first tie on Monday against reigning champions Croatia before also facing hosts Spain in Group B.