Although coach Jorge Sampaoli selected him in his first game in charge in June, he has left him out of all seven matches since.
But Messi believes he should be recalled in time for the World Cup in Russia. "He has to be there because he is key. He is one of the best strikers in the world and he has shown that every week at Juventus," the Barcelona player told Argentina broadcaster TyC on Wednesday.
Although Higuain is a regular scorer at club level, he has rarely reproduced that same form on the international stage, particularly in big matches.
But Messi believes the enforced layoff has had a positive effect on the striker, who turns 30 on Sunday.
"I think this time away from the national side has done him good and judging by the times we spoke, it has made him see things differently," Messi said.
Argentina, who have not won a major international trophy since lifting the Copa America in 1993, were last week drawn in Group D for next year’s World Cup finals in Russia, alongside Nigeria, Croatia and Iceland.
They won the tournament in 1978 and 1986.
(Reporting by Andrew Downie,; Editing by Neville Dalton)
