Tuipulotu has a tight hamstring, but Aki may have started ahead of him in any event.
Jones and Aki start in the midfield for the first time since the Queensland Reds game.
Hugo Keenan keeps his place at full-back, as do the underperforming wings, Tommy Freeman and James Lowe.
Andrew Porter takes over from Ellis Genge at loosehead, a move possibly intended to beef up the Lions bench.
It is an all-Irish front-row with Dan Sheehan and Tadhg Furlong.
With Joe McCarthy ruled out through injury, Ollie Chessum partners Maro Itoje at lock, with Farrell opting for the same back row that did such damage to the Wallabies on Saturday.
Morgan has been included among the replacements and will make his Test debut if and when he comes on at the MCG.
James Ryan, the Leinster lock, is also in, as are Farrell, who will cover fly-half and number 12, and Blair Kinghorn, who will cover full-back and wing.
The Wallabies welcome back heavy hitters Will Skelton and Rob Valetini along with hooker Dave Porecki.
Coach Joe Schmidt has gone with a 6-2 bench.
“We thoroughly believe that we’re way better than what we showed [in the first Test], and we’ve got another chance to prove that,” said Farrell.
“We’re the privileged ones that get the opportunity to do something special and hopefully create a bit of history.
“There’s a determined Australian side that’s going to try and stop us doing that, so it’s a hell of a test.
“No other Lions have done back-to-back victories of tours of the same country. So, due to the good work of the 2013 touring party, we get the privilege to be in a position to try and accomplish that.”
