Australian number one Bernard Tomic has accused team-mate Nick Kyrgios of faking illness to avoid the Davis Cup defeat by the USA in Melbourne.
Kyrgios, who missed a match against Czech Republic last year with a back injury, was absent with a virus.
"Twice he has faked it," Tomic was heard telling team captain Lleyton Hewitt during his game with John Isner.
But Hewitt said: "Nick gave everything he had to try to be available and there's no doubt he was sick."
Tomic made the comment, which was picked up by courtside microphones, during a changeover in his four-set defeat by Isner, which gave the USA an unassailable 3-1 lead.
"Nick's sitting down in Canberra," claimed the 23-year-old Germany-born world number 20, who later said he played with an injured wrist.
Kyrgios' withdrawal left Sam Groth to open the tie against world number 11 Isner at Kooyong Lawn Tennis Club, and the 28-year-old was beaten 7-6 (7-2) 6-2 6-2.
Tomic levelled the match but the Bryan brothers beat Hewitt - who came out of retirement to play - and John Peers to re-establish the advantage.
Isner's 6-4 6-4 5-7 7-6 (7-4) victory over Tomic put the Americans in the quarter-finals for the first time in three years.
Speaking after the match, Tomic said Kyrgios was on the entry list for the ATP event in Indian Wells, which begins on Thursday.
The 20-year-old played in the tournament last year, two weeks after sitting out Australia's match against the Czech Republic.
Tomic said he would "lose respect" for his former doubles partner if he competed there this year.
Kyrgios later sent a tweet which mocked Tomic's 28-minute loss to Finn Jarkko Nieminen at the 2014 Miami Open - the quickest match in ATP history.
"Let's not forget who holds the quickest loss on the ATP tour lol #how many minutes again," read the tweet, which Kyrgios later deleted.
He added: "Just don't expect me to have your back anytime soon."