Universidad de Chile captain Jose Oscar Rojas remains optimistic his side can still reach the Copa Libertadores final, but concedes they will need to play a "perfect match" against Boca Juniors tomorrow night if they are to overturn their 2-0 deficit from the first leg.

Boca took a giant step towards their tenth Libertadores final thanks to goals from Santiago Silva and Juan Sanchez Mino in last week's first meeting at La Bombonera. The Argentinian giants will now look to finish off the job tomorrow in Santiago and set up a final showdown against either Santos or Corinthians.

However, Universidad de Chile skipper Rojas is not giving the tie up for lost, although he knows his side need to produce something special in front of their own fans. He also knows how important it is to put the shackles on Boca star Juan Roman Riquelme if Universidad de Chile are to keep alive their hopes of a maiden Libertadores title. Rojas said of the veteran playmaker: "You give him 30 centimetres to play freely and he manages to set up a goal."

Rojas added: "We must play a perfect match in order to keep progressing. Boca are a team who knows how to play decisive rounds, but we have to believe in ourselves and be all together. We reached this stage because we had sacrifice and we must not let that slip in two games."

The Chilean side also have an impressive home record to fall back on, with the team having won their past 14 competitive matches at the Estadio Nacional. Coach Jorge Sampaoli knows it will not be straightforward though, saying: "The return game will be tough, because we suffered a score that is not easy to overcome."

We must play a perfect match in order to keep progressing. Boca are a team who knows how to play decisive rounds, but we have to believe in ourselves and be all together.

Jose Oscar Rojas, Universidad de Chile captain

Boca will be even more determined to claim a record-equalling seventh Copa Libertadores crown as their hopes of winning their domestic league are all but over after picking up just one point from their last two games. Sunday's 3-0 home loss to Arsenal saw them slip to third spot, two points behind their conquerors and Tigre, with only one round remaining.

Boca coach Julio Falcioni said: "Even though we have a mathematical chance (to win the Argentinian Clausura) and we are hopeful, we must focus on the Libertadores. Thursday's game will be very important to us. The league is not in our hands."

Boca will be without Argentina international defender Juan Manuel Insaurralde for tomorrow's game after he picked up an ankle injury in the defeat to Arsenal, and Falcioni admits fighting for honours on more than one front is taking it's toll. "We are playing double the amount of games the other teams are playing and we're suffering the consequences in the results and injuries. But, no excuses," said Falcioni, who will replace Insaurralde with Matias Caruzzo.

Universidad de Chile have also been hit by injuries, with defender Albert Acevedo and Argentinian midfielder Gustavo Lorenzetti sidelined. Igor Lichnovsky and Sebastian Ubilla take their spots.

The other semi-final will be decided tonight with Corinthians boasting a 1-0 lead over rival Brazilians and reigning Copa Libertadores champions Santos from last week's away leg.