File photo of Lionel Messi (left) with Luis Suarez.
Argentina and Uruguay go into Friday's Copa America encounter with neither team having won in three games since November.
The two sides seem unsure about which players to select for the Group A game at the Mané Garrincha stadium in Brasilia.
The winner could ultimately go on to top the group and avoid an early knockout-stage meeting with defending champion Brazil, which is in Group B.
Argentina coach Lionel Scaloni has received criticism since his team's opening 1-1 draw against Chile on Monday, a game that came a few days after a 2-2 draw with Colombia in World Cup qualifying.
Scaloni appears unsure whether to use three or four defenders against Uruguay. He could also bring back Cristian Romero in the center of his rearguard in place of Lucas Martínez Quarta.
If he opts for a line of three defenders, left-back Nicolás Tagliafico may miss out.
Scaloni is also undecided who should accompany Lionel Messi up front. Lautaro Martínez has been short of goals for Argentina while new Barcelona signing Sergio Agüero is eager to start.
Uruguay will have Luis Suárez and Edison Cavani in attack for its first game in the group, but coach Oscar Tabárez has not yet decided who will play in midfield between Giovanni González, who normally plays as a defender for Peñarol, Lucas Torreira, Rodrigo Bentancur, Nicolás de la Cruz, Federico Valverde, Matias Vecino, Facundo Torres and Jonathan Rodríguez.
If González plays, it could mean that Tabárez wants extra protection against the brilliant Messi.
Suárez said: “They are very strong up front but I can also make use of the frailties that every team has.”
Paraguay leads the group after beating Bolivia 3-1 on Monday.
