The Wallabies have been forced into another team shuffle with experienced prop Allan Alaalatoa withdrawing from camp due to a family bereavement, according to Sydney Morning Herald.
Alaalatoa becomes the fourth member from the Wallabies squad to fly home from Argentina after Michael Hooper (personal reasons), Dave Porecki (concussion) and Quade Cooper (Achilles) all returned to Australia over the last four days.
ESPN has contacted Wallabies management for confirmation.
Taniela Tupou is the next man in line, but it does open the door for Rebels tighthead Pone Fa'amausili to potentially make his Test debut after years on the fringes. It could also see the return of Tom Robertson to the Test line-up following his call-up after Scott Sio failed to overcome a shoulder complaint.
The reshuffle is another of many the Wallabies have been forced into this year with a growing number of players joining the injured list, while suspension and personal issues have also taken their toll. But the side has taken pride in their growing depth and ability to maintain high performances throughout the year.
"Every squad goes through periods where they are unlucky," utility back Reece Hodge said.
"Some teams get lucky through periods and they win, but the best teams win when they are going through periods that are quite tough.
"We have gone through one over the last two or three months but the fact we are developing great depth in the squad, and the next-man-up mentality we are developing, that will go a long way to hopefully getting performances together that we can be proud of.
"But also the most important thing in Test match rugby is winning matches."
Rennie will also face the tough decision of replacing Cooper. Noah Lolesio had a strong series against England, with several impressive performances, but James O'Connor will also be pushing for a return to the No.10 jersey.
O'Connor hasn't been sighted since the second Test defeat by England in Brisbane, when he endured a mixed cameo off the bench at Suncorp Stadium.
"We have two world-class No.10s," Hodge said. "Noah steered us to a series win against France last year and was very solid in that England series as well.
"James O'Connor has played 50-plus caps for his country and his form at the start of the season with the Reds was outstanding, he was probably one of the best players in the competition.
"So we have two really good options there."