Bernard Tomic has hit out at teammate Nick Kyrgios following Australia's exit to the USA in the Davis Cup.

The 23-year-old was caught by on-court microphones telling Aussie captain Lleyton Hewitt that Kyrgios's decision to sit out the tournament through illness was "bullshit".

"Nick's sitting down in Canberra," said Tomic. "Bullshit he's sick. Two times Nick's done it".

Tomic, who was referring to Kyrgios's withdrawal from the Davis Cup encounters with the Czech Republic last year, reiterated his stance when questioned by reporters at a post-match press conference.

"He didn't come to Czech and had stress fractures and somehow [then] played Indian Wells and felt good," Tomic said. "He said he's 'still sick but I'm going to be better tomorrow' – so it's just weird for me. If he plays Indian Wells, then he's definitely lost a little bit of my respect."

Tomic had lost his singles match to John Isner in four sets.