It was confirmed on Monday that Cahill will deputise for the injured Mile Jedinak as the Socceroos aim to secure their passage to the Asian Cup quarter-finals with a win at Stadium Australia.
They completed their preparations with a final training session at the venue the day before Tuesday's game, but suffered a scare when Chris Herd went down injured.
It appeared Herd – a contender for the vacant midfield role – twisted his ankle, immediately limping off under the attention of physio Les Gelis.
While it remains to be seen if Herd will be fit to face Oman, Cahill is a certain starter and will lead the side out in Sydney.
"I love playing for Australia regardless of which country I'm in, but to play at home in front of my hometown fans and see family and friends is very special," Cahill said.
"Not a lot of emotion comes into it when I cross that white line because it's going to be a massive game for us.
"Three points for either team changes the tide for where the group is. For us there's a lot on the line. We want to do well and we want to make sure we execute it in the right way.
"I've never needed an armband to lead this team, we take great respect that between the three of us [Jedinak and Mark Bresciano] that we do our best job to lead the side.
"It's a massive, massive honour and it's great in my career to have, but it's a great responsibility which I'll make sure I deliver in the right way."
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