Argentina's disappointing 3-0 loss to Croatia in Nizhny Novgorod on Friday morning (AEST) put the South American side in danger of missing out the on the World Cup Round of 16.

"Do not compare him (Cristiano Ronaldo) to Messi, because Messi’s uniqueness fades (when he’s) with the national team. Maybe the other players cannot adjust to him and this is my fault too," Sampaoli said.

The coach added that he does not feel "shame", but "true pain" after his team failed to beat Croatia, and Argentina need to "give everything in their final group game against to have any opportunity of advancing to the next round."

Croatia, who top the pool with six points, will next face Iceland in their final game Group D game.

Argentina only have one point from their first two games and have to beat Nigeria in their next and final game in Volgograd on Friday, to have a chance of making it to the Round of 16.