Former Inter and Argentina star Juan Sebastian Veron has questioned Jorge Sampaoli's decision to leave Mauro Icardi out of his World Cup squad, saying only the national team coach knows why the in-form goalscorer was excluded.

Icardi scored 29 goals in 34 Serie A appearances in 2017-18 – his most prolific season since joining the club in 2013 – but only featured in three of Argentina's World Cup qualifying matches.

Veron, who played for Inter on loan from Chelsea between 2004 and 2006 and made 73 appearances for Argentina, said he struggled to see why La Albiceleste would leave the 25-year-old forward behind.

"From outside it is difficult to judge his exclusion from the World Cup," Veron told RMC Sport. "I would need to be in the head of Sampaoli.

"I would have to be in Sampaoli’s head, but I do wonder why someone who has scored so many goals for Inter, who isn’t in the older generation, isn’t at the World Cup.

"He scores so much that he had to be on the list but only Sampaoli knows the reason."

Veron, who only retired from football in 2017 at the age of 41, said he hoped Lionel Messi's form would improve to help Argentina recover from a poor start to the World Cup, which has seen them take just one point from their first two games.

After a draw with Iceland and defeat to Croatia, Sampaoli's men must beat Nigeria in their final Group D game to stand a chance of reaching the knockout phase – a feat they have not failed to achieve since 2002.

Final del partido. cayó ante por 3 a 0. June 21, 2018

"I hope they go through to the second round," he said. "It's not an easy situation.

"What has happened to Messi? Only he knows. I hope he can drag the team and the team can accompany him.

"One player alone can not solve the fate of a team."