"We expect this to be a very difficult match," he told a news conference at Soccer City on Thursday.
Uruguay, twice World Cup winners, are bidding for a place in the last four for the first time in 40 years.
Ghana, the only African side left in the tournament, are bidding to become the first from the continent to reach the semi-finals.
"In World Cup matches, as one progresses, the teams are increasingly even. Ghana are very strong, very fast players with good dribbling when they run with the ball. We know it will very difficult," Tabarez said.
Uruguay, who beat hosts South Africa in the group stage, plan to hit the ground running.
"We won't wait for Ghana to score a goal before we start to play the way we should be," Tabarez said. "We have great respect for our opponents but our ambition is to be in the semi-final.
"We won't become complacent, that would be suicidal. All the matches are final matches. And you have to score goals."
Tabarez, who retains the thoughtful air of the school teacher he once was, fielded repeated questions about the weight of history on the national side and the expectations generated by this World Cup run.
The glory days when they won the World Cup in 1930 and 1950 are distant memories and La Celeste last reached the semi-finals in 1970. The small nation of just three million people has long been overshadowed by giant neighbours Brazil and Argentina.
"If I think about, I become overwhelmed. I don't want to think about it. We must not lose concentration. We have to focus on tomorrow and the present and we can think about history later," said the coach known as The Master.
GENTLY SCOLDED
However, pushed again by a Brazilian journalist, he gently scolded: "Let's not talk about Maracana. It's history."
He was referring to 1950, when Uruguay beat an extremely confident Brazil team in Rio de Janeiro's Maracana stadium to be crowned champions.
Should Uruguay reach the semi-finals, they would face Brazil if their fellow South Americans beat the Netherlands.
Uruguay's strength has been based on in-form strikers Diego Forlan and Luis Suarez and a robust defence marshalled by Diego Lugano, which has given away only one goal in four games.
Tabarez also acknowledged that Uruguay were carrying the dreams of a nation and he looked emotional as he spoke of the deeply engrained passion for football in the country.
"The most important present you can give a child, like at Christmas, is a soccer ball, even if it is made of rubber or cloth," he said. "Parties, celebrations...let's hope we can have some tomorrow."
Meanwhile, fans have been coming across the Atlantic and some were allowed to watch the team training in the magnificent Soccer City stadium as night fell.
Martin Lijouri, a 29-year-old engineer from Montevideo, had come with his family.
