Interim Argentina coach Lionel Scaloni is uncertain when Lionel Messi will play for his country again.

Messi was left out of the squad for next month's friendly matches with Guatemala and Colombia, with his long-term international future reportedly in doubt.

The Barcelona star retired from Argentina duty after losing the Copa America final in 2016, only to reverse the decision and lead his country to the 2018 World Cup finals, where they were knocked out in the last 16 by eventual winners France.

After that disappointment in Russia, which led to the departure of coach Jorge Sampaoli, Messi is thought to be considering whether or not to quit international football for good.

Scaloni has confirmed he spoke to the 31-year-old before announcing the latest squad, but says he does not know what the future holds for the five-time Ballon d'Or winner.

"I talked to Messi and, based on that chat, he is not in the squad for these two matches," Scaloni told a news conference. "Honestly, we didn't talk about what can happen in the future.

"We all know what he represents for us. I have a good relationship with him and we were both very clear. He's not in the squad and, in the future, we'll see. We have more matches to play and we'll see.

"It can't be better for any coach in the world if Messi isn't there... It would be most imprudent on my part to tell him to stay in Barcelona and not come [to the national team]."

Sergio Aguero, Angel Di Maria, Gonzalo Higuain and Nicolas Otamendi are among a number of other senior players not to be included in the latest squad.

Instead, Inter captain Mauro Icardi has earned a recall, while exciting youngsters Lautaro Martinez and Giovanni Simeone are also options in attack.

"Icardi, Martinez and Simeone are players of a huge level," said Scaloni. "Mauro is the one who has spent the longest among the elite, but all of them can help. I have complete faith in them."