Pumas five-eighth Nicolas Sanchez and winger Manuel Montero must pass last-minute fitness tests before Argentina take on Australia in Saturday's Rugby Championship clash at Twickenham.
Sanchez (ankle) and Montero (leg) have been included in the side named by coach Daniel Hourcade.
"This is the team that will play (but) we have to wait a bit to see how Nico and Manu evolve," Hourcade said.
Montero is coming back from the leg injury that put him out of the last three matches having played in the first two, an away defeat and home win against South Africa.
Sanchez, Argentina's chief place kicker and second behind New Zealand's Beauden Barrett with 53 points in five matches in the tournament, has been ever present.
Jeronimo de la Fuente, named on the bench, stands by to come in at inside centre with Santiago Gonzalez Iglesias moving to flyhalf.
Ramiro Moyano, also on the bench, will be reprieved if Montero pulls out.
Montero is due to replace Moyano on the left wing, with Matias Moroni moving to the right flank instead of the injured Santiago Cordero. Matias Orlando has been picked at outside centre.
In the pack, Lucas Noguera comes in for the injured Nahuel Tetaz Chaparro while Leonardo Senatore replaces Facundo Isa at number eight.
Prop Santiago Garcia Botta will make his tournament debut if he comes off the bench.
Should Sanchez and Montero drop out, Gabriel Azcarate and Lucas Gonzalez Amorosino will be added to the bench.
"The team has some players out due to a very intense year of very hard matches and they are feeling the wear and tear," Hourcade said.
"But we are very motivated playing at Twickenham again and focused on having a great match."
The game will be a repeat of the 2015 World Cup semi-final a year ago at the same venue, won 29-15 by the Wallabies.
Australia takes on Argentina at Twickenham on Sunday morning at 5:30am AEDT.
1. Lucas Noguera
2. Agustin Creevy,
3. Ramiro Herrera
4. Guido Petti
5. Matias Alemanno
6. Pablo Matera
7. Javier Ortega Desio
8. Leonardo Senatore
9. Martin Landajo
10. Nicolas Sanchez
11. Manuel Montero
12. Santiago Gonzalez Iglesias
13. Matias Orlando
15. Joaquin Tuculet
16. Julian Montoya
17. Santiago Garcia Botta
18. Enrique Pieretto
19. Marcos Kremer
20. Tomas Cubelli
21. Juan Manuel Leguizamon
22. Jeronimo de la Fuente
23. Ramiro Moyano