Ireland coach Joe Schmidt oversaw an historic clean sweep of the November tests - despite suffering from a bout of appendicitis.
The Kiwi masterminded an astonishing 26-23 win against Australia but later was too ill to attend the post-match press conference.
"He really manned up today," said an IRFU spokesman. "And it was touch and go at one stage during the day. He is off to get some tests done this evening."
Ireland completed a clean sweep of November tests for the first time in eight years, hardening their status as World Cup contenders as they secured their ranking at number three in the world.
Ireland captain Paul O'Connell revealed that the Ireland squad didn't know how sick heroic coach Joe Schmidt was - despite being sent to hospital after the game for tests on suspected appendicitis.