Lionel Messi has expressed his disappointment at hosts Argentina's 1-1 draw with heavy underdogs Bolivia in their Copa America opener in La Plata.

La Verde may have shocked the two-time global kings with a 6-1 rout in 2010 FIFA World Cup South Africa™ qualifying, but that was at high altitude. Here, there could be no excuses as Edivaldo Rojas gave the Bolivians a deserved whiff of a first-ever win on Argentinian soil after 11 losses, before Sergio Aguero rescued a point with a crisp late volley.

"They put men behind the ball, parked the bus and we could not find a way through," said Messi, who despite his heroics with Barcelona in scoring over 50 goals last season has never quite reached the same heights when he has donned the Albiceleste shirt.

"It's not what we were hoping for and we are sad. Now we know the matches we have to come in the group (against Colombia and Costa Rica) are ones we just have to win."

It's not what we were hoping for and we are sad. Now we know the matches we have to come in the group are ones we just have to win.

Lionel Messi

Bolivia were determined not to be the fall guys in Group A and this draw means they can also hope to get through from the group phase. Meanwhile, Messi said Argentina must go back to the drawing board.

"We must see what we did well and sift through what we did badly [to] try and get back to winning ways," he said. "We must keep calm. We haven't started off as well as we hoped, but now we simply must up our game in the coming matches."

Aguero, Tevez urge improvement
Aguero credited Bolivia's fighting spirit. "Now we have to do a bit better as they made it hard for us, though I thought we started off all right before they got the goal," said the Atletico Madrid striker and son-in-law of former Argentina coach Diego Maradona, who dedicated his goal, as ever, to his family.

Carlos Tevez, for his part, urged Argentina to work hard to avoid falling flat on their faces as they seek to end a barren trophy run stretching back to 1993, when they won the Copa America in Ecuador.

"We knew this would be a tough Copa," said the Manchester City forward. "We need to keep calm and keep things in perspective, as if we lose heart it will be worse for us. Today we were short on goals, we didn't gell well in attack or have much mobility, but we do know what we are trying to achieve and how we want to approach our game."

Argentina have lifted a joint-record 14 Copa America titles alongside Uruguay, while Brazil have won the competition eight times, including four of the last five.

Sergio Batista's team now have five days to plot a way past unpredictable Colombia in Santa Fe, before they go up against Costa Rica, special guests in the absence of original invitees Japan.