Usman Khawaja has held out Shaun Marsh to keep his spot in Australia's top order, with Afghanistan winning the toss and batting first in their World Cup opener.
In what will coincide with Steve Smith and David Warner's long-awaited returns, Khawaja will bat at No.3 for Australia.
"Usman's form over the last 14 or 15 games is just too hard to ignore, he has been in great touch," captain Aaron Finch said.
"So has Shaun to be honest, it was a really tough but unfortunately Shaun misses out."
Neither Warner or Smith have played an official international for Australia since the ball-tampering scandal and subsequent bans following the ill-fated tour of South Africa last year.
Warner was forced to pass a fitness test on a minor glute strain earlier in the week, but officials are confident he will not have any lingering issues.
Finch also confirmed Nathan Coulter-Nile had won the race to be Australia's fourth bowler, with the Aussies opting to go with three quicks in Bristol.
Afghanistan also confirmed dangerous wicketkeeper-batsman Mohammad Shahzad had overcome a hamstring injury to play.
Australia beat Afghanistan by a World Cup record margin of 275 runs when they last met in the 2015 tournament, but the minnows are expected to be a different challenge on Saturday.
They have three of the game's best spinners in Rashid Khan, Mujeeb Ur Rahman and Mohammad Nabi, however all will have to contend with the tiny boundaries in Bristol.
AUSTRALIA: Aaron Finch (capt), David Warner, Usman Khawaja, Steve Smith, Glenn Maxwell, Marcus Stoinis, Alex Carey (wk), Nathan Coulter-Nile, Pat Cummins, Mitchell Starc, Adam Zampa.
AFGHANISTAN: Mohammad Shahzad (wk), Hazratullah Zazai, Rahmat Shah, Hashmatullah Shahidi, Najibullah Zadran, Mohammad Nabi, Gulbadin Naib (capt), Rashid Khan, Dawlat Zadran, Mujeeb ur Rahman, Hamid Hassan.
