Argentina manager Lionel Scaloni said Lionel Messi's status for its Copa América quarterfinal against Ecuador on Thursday is unclear.

The World Cup-winning coach said the lineup would be determined after the evening training session, in which Messi took part.

"We will train in a couple hours, and then we will decide. One more day is always better, yesterday we had good sensations and today we will decide. Based on today's answer [In training], we will decide if Messi plays," he said in a news conference before practice.

Messi did not play in Argentina's final group stage match -- a 2-0 win over Peru on June 29 -- due to a right leg injury sustained in its 1-0 defeat of Chile. His status was described as "day to day" before returning to training earlier this week.

Scaloni expects to have an individual conversation with Messi after the last session and before the match to further understand his physical status.

"I haven't spoken with him about the situation, I will talk to him today given it's match day -1," Scaloni said. "I thought it was fair that he took his time and train as much as possible. After talking, we will decide. I haven't talked to him, so we don't know if he will play."

Though Scaloni is not sure how his team will line up against Ecuador, he maintained the decision to start certain offensive players over others will not be impacted by the presence of Messi.

"It's never been that way. It alters when Leo doesn't play, it alters everyone, not just me," Scaloni said. "We will try for him to be there, and if not we will find the best for the team. He's game by game, and the team will conform to the rival."

Lautaro Martínez and Julián Álvarez previously played together when the team faced Ecuador in a pre-Copa America friendly on June 9, leading the way in a 1-0 win as Messi watched from the bench.

Scaloni warned against overanalyzing that friendly ahead of the knockout match tomorrow, saying "every game has its own story."

"They've played together against this rival, and we will decide after today's training," Scaloni said. "They've worked well, and it's an option. But we will see how everyone is today, especially Leo, and we will see.

"That game has nothing to do with [the friendly result]. It's a completely different game, with different players I imagine. But every game has its own story. We analyzed and watched the game, but we think it'll be different. No game is the same, but we will play in a similar fashion."

However, Ecuador manager Félix Sánchez said his team studied the June 9 game, as well as other matches against Argentina when preparing for the quarterfinal.

"We know the team we face is of maximum level, Messi is a differential player, the one that marks the most difference today," Sánchez said. "But Argentina's game model doesn't change much with or without him. They've been with Scaloni for a while and developed a signature playing style with and without Messi on the field.

"We cannot repeat the game we had against [Argentina] in Chicago. We have analyzed that game, and all we've faced against them."

The two sides will face off at NRG Stadium in Houston, Texas, on Thursday, with the winner advancing to the semifinal at Metlife Stadium in East Rutherford, New Jersey, on July 9.