Australia spinner unavailable for second Test against Sri Lanka
The 28-year-old will fly home after failing to recover from a side strain and has been replaced by left-arm finger spinner Jon Holland.
Agar, who hasn't played a Test since 2017, was not considered for the first Test against Sri Lanka either, with leg-spinner Mitchell Swepson in the XI. Australia won the first Test by 10 wickets.
Australia captain Pat Cummins was impressed with Swepson's bowling and praised the leggie after their comprehensive victory under three days.
"Really happy with Swepo," said Cummins. "A couple of key breakthroughs in the first innings and then today, top-order wickets.
"Really valuable, I thought he controlled the tempo of the game, he had some batters come really hard at him. I thought he bowled beautifully."
Interestingly, Agar's replacement Holland himself is nursing an injury. He hurt his finger before the second Australia A four-day match against Sri Lanka A but is on the road to recovery and in with a chance to be considered for the final match of the tour.
35-year-old Holland, who made his debut in 2016, has featured in only four Tests so far, picking up nine wickets. His last Test was against Pakistan in October 2018.
The second and final Test will be played in Galle from 8 to 12 July.