La Serena - Lionel Messi has warned his Argentina team-mates that Tuesday's Copa America clash with Uruguay is a must-win encounter after their stumbling draw with Paraguay.
The tournament favourites were left stunned on Saturday after they let a 2-0 lead slip as Paraguay snatched a 2-2 draw with a last-gasp equaliser in Group B.
Argentina's shaky defensive display in the second half has reawakened doubts about their ability to produce a title-winning performance in Chile, where they are chasing a first major championship in 22 years.
Messi, who had a hand in one of Argentina's goals before scoring the second from the penalty spot, could not hide his fury after what looked like being a comfortable opening victory ended in a draw.
"To be leading 2-0 and to end up with a draw makes me angry," the Argentina captain said.
"Looking at it now, you have to say that the Uruguay match is one we absolutely have to win," he added.
Defending champions Uruguay opened their campaign with a lacklustre 1-0 win over Jamaica on Saturday.
With Argentina still to play Jamaica in their final game, a win over Uruguay on Tuesday could give Messi's men a strong chance of topping the group -- and avoiding a possible quarter-final meeting with Brazil.
But the Argentinians will be wary of the threat posed by Uruguay, who knocked out their neighbors on home soil four years ago.
Messi said Argentina had failed to react when Paraguay opted for a more attacking approach in the second half on Saturday.
"In the first half we controlled the game, we created chances and we scored. Then everything changed in the second half when they started to play better," Messi said.
Argentina coach Gerardo Martino also raised eyebrows by bringing on strikers Gonzalo Higuain and Carlos Tevez towards the end of the second half instead of bolstering his midfield to stifle the Paraguay threat.
"We needed to put our foot on the ball," Messi said.
Martino meanwhile struck a defiant tone, insisting his team did not need to change their approach.
"We lost control of the game, that's all, but we could have won 5-2," he said.