The second leg match between the fifth placed South American team and fourth place CONCACAF side will mark the end of a qualifying phase that has lasted over two years.
For the winner, the long journey will have been worth it, but for the loser, another four years awaits them for their next chance.
"We're used to suffering, to winning in the final minutes, so once again we're going to have to go to the stadium with the same obstinacy," Uruguay midfielder Diego Perez told a news conference on Monday.
They are in the box seat to qualify again this time after beating Costa Rica 1-0 in San Jose in Saturday's opening leg after their captain Diego Lugano scored the only goal.
"It's been more than two years of a very hard elimination series, there are two days and 90 minutes to go," Lugano said.
"We can't let this opportunity escape us. On Wednesday we have to give the (Uruguayan) people happiness."
"The Centenario is a stadium with a lot of history, which always pushes you forward and we hope Wednesday will be a day of glory for Uruguayans," said Lugano.
They have, however, encountered an internal problem in the build-up with forward Froylan Ledezma quitting the team's headquarters before they flew to Montevideo on Sunday. He did not play on Saturday.
"Froylan Ledezma's decision has been taken as an act of indiscipline, so as from this moment the case is being handed to the disciplinary committee," the Costa Rican federation's general secretary Joseph Ramirez was quoted as saying on its website.
Costa Rica's Uruguayan physical trainer Marcelo Tulbovitch, who replaced suspended coach Rene Simoes on the bench in San Jose, said the team had overcome the disappointment of their home defeat and were confident for the return.
"It's not written that we can't win (in Montevideo), we've already started to lift the lads' morale, we'll recover and get (to the match) in good shape. It's the world final," he said.
