Argentina coach Gerardo Martino has voiced his concerns after his side squandered a two-goal lead to Paraguay in the Copa America.

The tournament favourites led 2-0 at half time thanks to goals from Sergio Aguero and Lionel Messi, but Nelson Valdez and Lucas Barrios rescued a point for Paraguay.

Martino also brought on Carlos Tevez and Gonzalo Higuain before Paraguay's fightback, and told reporters that his side appeared to lack confidence.

He said: "What worries me most are the two extremes that the team played at. It is clear we need to play games with absolute control, even we had some matches were we haven't had too much control we didn't suffer a lot.

"I have the feeling today we lost the control and the opponent had four or five chances, which let them draw."

Argentina resume their campaign on Tuesday when they face defending champions Uruguay.