Having already been knocked out of South America's premier club competition, both teams will now battle it out for a place in the Copa Sudamericana.
Match preview
Barcelona SC played out a goalless stalemate in their last continental outing against Brazilian side Sao Paulo at Estadio Do Morumbi on May 17.
Ariel Holan's men were under the cosh for the vast majority of the clash but held firm to come away with a share of the spoils thanks to some defensive heroics.
Idolo del Astillero have won all of their three subsequent league outings and sit second in the Liga Pro table, one point shy of Independiente del Valle.
Next up is the challenge of an opposing outfit who battled hard for a 1-1 draw in the only previous edition of this fixture back in April.
Unbeaten in eight of their last nine home matches, Thursday's hosts have shown they are certainly no pushovers in front of their fans and will back themselves to come out on top here.
Cobresal fell to a narrow 1-0 defeat against Talleres Cordoba when the teams went head to head at Estadio Mario Alberto Kempes on May 14.
Gustavo Huerta's men looked set to secure a hard-fought point as the game headed into its final knockings still goalless before Federico Girotti struck a late winner.
With just one point picked up from their five Copa Libertadores matches so far, El Milagro del Desierto sit bottom of Group B, albeit just two points shy of their next opponents.
Boasting just one victory across their last 11 matches on the road, Thursday's visitors have it all to do as they look to avoid another fruitless outing on the road.
Barcelona SC Copa Libertadores form:
D
D
L
L
D
Barcelona SC form (all competitions):
L
D
D
L
L
D
Cobresal Copa Libertadores form:
D
L
L
L
L
Team News
Barcelona's Francisco Fydriszewski has scored six times in his last seven appearances and will be aiming to deliver the goods once again.
Franklin Guerra remains sidelined for the hosts with a knee problem he picked up in a friendly matchup against New York City earlier this year.
Cristian Toro was hauled off in Cobresal's defeat to Talleres last time out and remains a major doubt for this one having missed the last two matches.
Leonardo Rossel is one to keep an eye on here as the midfielder heads into Thursday's clash on a two-game scoring streak for the visitors.
Barcelona SC possible starting lineup:
Burrai; Chala, Sosa, Ramirez, Rangel; Trindade, Arroyo, Gaibor; Lopez, Quintero, Fydriszewski
Cobresal possible starting lineup:
Requena; Jorquera, Alarcon, Bechtholdt, Filla; Mesias, Cespedes, Rossel; Munder, Carrasco, Garcia