The tighthead prop will fly home due to personal reasons and miss the second Test against Argentina on Sunday morning (AEST).

Alaalatoa is the fourth player to depart the squad in the past week. Hooker Dave Porecki suffered a concussion at training, while Quade Cooper tore his Achilles in the Wallabies victory over the Pumas last weekend.

Captain Michael Hooper was a late withdrawal from that encounter and has since returned home to manage his mental wellbeing.

The injuries continue a wretched run for the Wallabies, numerous players going down in the England series.

Loosehead prop, and stand-in captain, James Slipper switched over to tighthead during that series, however it's likely he will remain on his preferred side of the scrum this weekend.

That leaves Taniela Tupou in line to step into the starting team as Alaalatoa's replacement on Sunday.

Rebels prop Pone Fa'amausili shapes as another option, the rookie in the frame for his maiden Test cap.

Alaalatoa's departure from the squad comes as the race for the vacant No.10 jumper heats up.

Reece Hodge replaced Cooper last weekend, however the 27-year-old expects to maintain his position as a bench utility.

Instead, he feels it's a battle between Brumby Noah Lolesio and James O'Connor to start on Sunday and Hodge backed both men to excel if given a shot.

"Quade's a very experienced player and he's an expert at getting the best out of people around him so we're not hiding the fact that it's a massive loss for us," Hodge said.

"But Noah steered us to a series win against France last year and was very solid in that England series as well.

"And then James has played 50-plus Tests and his form at the start of Super Rugby season for the Reds was outstanding; he was probably one of the best players in the competition early on so we've got two really good options heading into the game this weekend."