"The qualifier at Lisbon is without doubt a match of great importance both for the Russian squad and for our opponents," the Italian manager was quoted as saying in a Russian Football Union (RFU) statement.
"A positive result in this clash will definitely bring us closer to our main goal -- a place in the World Cup finals. Participation in the World Cup is a matter of vital importance for all of Russian football as it may give a powerful boost for its further development."
Russia, who failed to qualify for the last two FIFA World Cup finals, have set up their training base in Marbella, Spain, to prepare for Friday's match. Capello's side currently top the European qualifying Group F with 12 points from four matches, one point ahead of Portugal and Israel, who share second spot both after six games.
Zenit St Petersburg midfielder Roman Shirokov said he expected Portugal to attack in the same way they did during their last meeting in Moscow last October, which the home side won 1-0.
"We're going to Lisbon for the win even if we have to defend throughout the match. We're set to obtain a positive result in this match. And the only positive result for us is a win," he said.
GoalkeeperIgor Akinfeev, who won the Russian title with CSKA Moscow, assessed that Russia have a fair chance to make the finals -- but it was entirely in their hands.
"We already proved that we're able to overcome Portugal," he said in an interview with the Sport-Express newspaper. On Friday we expect an even more difficult match than we played in Moscow but our desire to win is even stronger. We have a great chance to solve all the problems and we are set to convert this chance into reality."