"I still believe a lot in these players that have taken us to three finals", he added, referring to one World Cup and two Copa America finals.
In contrast to Ronaldo's four goals, Messi is yet to get off the mark as Argentina have drawn with Iceland and lost to Croatia, leaving them needing a win against Nigeria to keep their hopes of making the last 16 alive.
The 57-year-old won the World Cup trophy with Argentina in 1986.
However, bouncing back will take a huge improvement in performance and strength of character so far unseen from the two-time world champions in Russian Federation.
"He does not have the quality in behind him, when he needs someone who can help him build up the play".
If there is one trophy that makes Lionel Messi "one of the" and not "the" Greatest Of All Time (G.O.A.T) in football is the FIFA World Cup or any other worldwide major for his country.
Instead it has been a poor world cup, with reports suggesting that the players are calling for the manager to be removed ahead of their final group game.
"I'm furious and very upset inside, because anyone who has worn that shirt can't see it being trampled like that by a Croatian team that isn't Germany, that isn't Brazil, that isn't Holland or Spain".
And perhaps the most striking observation you can make between the two at the World Cup, is their contrasting reactions to their national anthems.
Argentina almost missed the World Cup altogether, needing a Messi hat-trick in the final qualifying match just to punch a ticket to Russian Federation.
Tapia was at a news conference on Sunday with midfielder Javier Mascherano, who denied there was a rift between Sampaoli and the players.
So far in Russia, Messi has been held scoreless.
Argentina must beat Nigeria to have any chance at advancing past the group stage.
"The Argentina game will be completely different though".