The 25-year old was set to play a crucial role for Argentina in the World Cup this summer.
Lanzini, who battled a persistent knee injury towards the end of the Premier League season, started Argentina's 4-0 friendly win against Haiti at the end of May.
The attacking midfielder, who earns £70,000 per week as salary according to The Daily Star, is a very important player, and West Ham will hope that he returns to action as soon as possible.More news: Life on Mars? Curiosity rover finds 'most compelling' evidence yet
However, his participation in Russian Federation has been cruelly ended after suffering a knee injury in training on Friday, as confirmed by the South American giants official Twitter account.
Lanzini was named in Jorge Sampaoli's 23-man squad last month but has now been ruled out after rupturing an anterior knee ligament. Lanzini has earned four caps to date and scored his first senior global goal in a 2-0 friendly victory over Italy. An injury like this could also see him out for a portion of the EPL season with West Ham.
They will now have to deal with a new player being drafted in after Lanzini's serious injury.