The reigning Copa America champion occupies the fourth and final automatic qualification spot for Brazil, but finds itself level on points with fifth-placed Chile and just one ahead of sixth-placed Venezuela.
Having conceded seven goals in away defeats to Colombia (4-0) and Argentina (3-0), La Celeste's defence will be stretched further in the Bolivian capital with captain Diego Lugano, Diego Godin and Martin Caceres all ruled out through suspension.
Lugano, who helped guide Uruguay to the semi-finals in South Africa two years ago, said victory is essential: "Now every game for us is like a final because our World Cup qualification is in danger."
Uruguay will have little time to adjust to the altitude - the Estadio Hernando Siles is some 3,600 metres above sea level - but Pereira says that can't be used as an excuse.
However unlike Ecuador, which has turned its Quito stadium into a fortress, Bolivia's home qualifying record is far less impressive with just one win from four matches.
Xabier Azkargorta's side realistically needs three points to keep its quickly-fading hopes alive.
Argentina, unbeaten in its past six qualifiers, can take another step towards clinching its place in the finals when it faces a depleted Chile in Santiago.
Chile succumbed to Ecuador in Quito last week, but the repercussions of that defeat have also left Claudio Borghi without midfielder Arturo Vidal and Pablo Contreras - both players were sent off - while Osvaldo Gonzalez is also suspended after accruing his second yellow card of the campaign.
Argentina, which leads the standings with 17 points from eight matches, has injury concerns of its own after Gonzalo Higuain (hip) and Marcos Rojo (hamstring) were forced off during La Albiceleste's 3-0 win over Uruguay.
However, Alejandro Sabella does have an in-form Lionel Messi at his disposal.
Since Sabella's arrival, the Barcelona superstar has tallied 13 goals in as many matches and received widespread acclaim for his two-goal performance against Uruguay.
Messi was also on the scoresheet when Argentina won the reverse fixture 4-1 in Buenos Aires last October, and the 25-year-old is just four shy of Diego Maradona's 34 international goals.
Elsewhere, Venezuela is one point from an automatic berth as it prepares to host Ecuador.
Ecuador will be without the suspended Felipe Caicedo, who scored twice in last week's 3-1 win over Chile and has four goals in his past three matches for his country, but Antonio Valencia is available again after his one-match ban.
Paraguay and Peru meet in Asuncion in the other match.
Paraguay is bottom with a mere four points having lost five qualifiers in a row, its worst run since the current system was introduced in 1996, while seventh-placed Peru lies on eight points.