Nick Kyrgios claims he has been thrown "under the bus" by Lleyton Hewitt following his decision to withdraw from Australia's team at the United Cup.
Kyrgios pulled out of the joint ATP and WTA event on Wednesday — less than 24 hours before it began — due to an ankle injury.
Hewitt, who is Australia's co-captain at the United Cup, said on Thursday he had been unaware of Kyrgios's withdrawal until the 27-year-old's announcement.
He was unimpressed by what he described as a "lack of communication" from Kyrgios.
On Friday, Kyrgios took a swipe at Hewitt on Twitter when he replied to a tweet highlighting Australian Ajla Tomljanović's withdrawal from her United Cup match against Great Britain's Harriet Dart because of a left knee injury.
Kyrgios queried if Tomljanović would have been treated similarly by Hewitt's co-captain Sam Stosur.
"Mmm I wonder if Stosur will throw her (Tomljanović) under the bus like our captain did for me … 'hard to prepare when you don't know what's going on'," Kyrgios wrote.
Kyrgios was set to represent Australia for the first time in a team competition in almost three years.
The men's world number 22 trained on the practice courts at Sydney Olympic Park on Friday.
In Kyrgios's absence at the United Cup, Great Britain built an unassailable lead to win the tie against the understrength Australians on Ken Rosewall Arena at Sydney Olympic Park.
Maddison Inglis, who took Tomljanović's spot, lost her women's singles rubber to Dart, 6-4, 6-4.
Alex de Minaur, who replaced Nick Kyrgios as Australia's top men's seed, was defeated by Cameron Norrie in Thursday's opening men's singles rubber, 6-3, 6-3.
Norrie's countrywoman Katie Swan backed up his win when she downed Zoe Hives, 6-4, 6-3.
In the men's singles rubber on Friday night, Australia's world number 107 Jason Kubler scored an upset win over 27th-ranked Dan Evans, 6-3, 7-6 (7/3).
Among other results in the opening round-robin ties, the United States beat Czech Republic, Switzerland defeated Kazakhstan, while Italy got past Brazil.
Greece also triumphed over Bulgaria.
Reuters/ABC
