The visitors have numerous players one booking away from suspension against a side whose hopes of reaching Brazil are also in the balance.
Oscar Tabarez's charges are locked in a tight battle in the South American World Cup 2014 qualification table, having finished fourth at the 2010 tournament in South Africa.
They currently hold fifth place in CONMEBOL with 22 points from 14 matches, while opponent Ecuador occupies the last automatic qualification spot but only leads Friday's visitors by virtue of goal difference.
A loss for Uruguay would leave its top-four hopes in jeopardy, with a showdown against Argentina in Montevideo awaiting in the final match. Uruguay will draw confidence from its most recent doubleheader against Peru and Colombia in September, though, which yielded a vital six points.
It will be mindful of the fact that a whole host of players in the squad face the possibility of missing the Argentina match if they pick up another caution. Paris Saint-Germain striker Cavani is joined by other experienced players such as Walter Gargano, Maxi Pereira and Gaston Ramirez in treading a fine line for the fixture in Quito.
Ecuador has six victories to its name, but its hopes of securing a place in Brazil have been hit by a failure to win its last four qualifiers.
Crucial to their hopes will be the form of Felipe Caicedo, who has six goals to his name in qualification so far, while Manchester United winger Antonio Valencia is also included in the squad.