Argentina coach Jorge Sampaoli is confident of a fresh Barcelona star Leo Messi for the World Cup.

Sampaoli admits Messi is always the first name of his selection list.

"I think Messi is very optimistic, excited about what is ahead," Sampaoli insisted as he announced the squad. "Physically he's very good, winning the league early influenced that.

"We won't count on Messi much for the friendly matches but I think for the World Cup he will be very good."

The coach added that he is already beginning to pick his starting line-up for the tournament.

"We have an idea, but we are very far from the XI for the opening game, it will change for sure, because of everything that happens day to day," he admitted.

"The World Cup is a challenge where if you don't have everything you're doing clear then it will cause you problems. You have to face up to it without fear."