Both sides, who are currently level on eight points, will head into the winner-takes-all contest looking to get one over the other and book their spot in the playoffs.
Match preview
Internacional made light work of 10-man Real Tomayapo on Wednesday as they picked up a comfortable 2-0 victory over the Bolivian outfit in the Copa Sudamericana at the IV Centenario Stadium.
In a game where Juan Orellana received his marching orders, Bruno Gomes put the visitors ahead a minute after the half-hour mark before former Frankfurt man Lucas Alario made sure of the result with an 89th-minute strike.
Prior to that, Eduardo Coudet's men returned to action in the Serie A after a one-month break on June 1 when they scraped a 1-0 victory over Cuiaba courtesy of a second-half strike from Hugo Mallo.
With Wednesday's result, Internacional have now picked up two wins and two draws in their five Copa Sudamericana matches to collect eight points and sit third in Group C, level on points with Sunday's visitors.
After two consecutive victories on their travels, the Red will need to show their mettle this weekend as they have won just one of their last five home matches in all competition while losing twice and claiming two draws since March.
Delfin, on the other hand, picked up three huge points in their push for a place in the Copa Sudamericana knockout stages as they edged out Real Tomayapo 4-3 when the sides met on May 29.
They found themselves trailing 3-2 at the half-time break, but Mariano Mino and Jose Angulp scored quick-fire goals in the second half to turn the game on its head at the Estadio La Cocha.
Prior to that, Juan Pablo Buch's side kicked off their quest to conquer the continent with a 2-0 victory over Tomayapo in Bolivia on April 5th before picking up just two points from their subsequent three outings.
El idolo de Manta head into Friday's crunch tie off the back of a narrow 1-0 defeat at the hands of Cumbaya FC in the Ecuadorian Serie A, where they are currently 15th in the table with just nine points from their opening matches.
While Delfin will be looking to edge out International and finish as runners-up in Group C, they have failed to win any of their last five away matches in all competitions, losing four and claiming one draw since April's 2-0 victory at Tomayapo.
Internacional Copa Sudamericana form:
D
D
W
L
W
Internacional form (all competitions):
L
W
D
L
W
W
Delfin Copa Sudamericana form:
W
W
D
L
D
W
Team News
Internacional remain without the services of goalkeeper Ivan, who continues his lengthy spell on the sidelines after sustaining a cruciate ligament injury in January.
He is joined on the club's injury table by 29-year-old forward Wanderson, who has missed each of the last five matches after coming off with an ankle injury in April's game against Atletico Paranaense.
Fellow attacker Luca missed the game league clash with Cuiaba last time out due to injury and the 21-year-old is also a doubt for this weekend's encounter.
As for Delfin, Erick Zuniga was forced off injured midway through the game against Cumbaya last time out and the 21-year-old forward is a doubt for Friday's matchup.
Should he fail to shake off the injury, experienced striker Jostin Alman should come into the fold, forming the attacking trio with Marcos Mejia and Independiente loanee Nicolas Messiniti.
Internacional possible starting lineup:
Fabricio; Rene, Reges, I Gomes, Bustos; Maia, B Gomes, Hypran, Mauricio; Patrick, Alario
Delfin possible starting lineup:
Bellolio; Elordi, GariglioC Goitea, Cuero; Sambonino, Humanate, Mieles; Alman, Mejia, Messiniti
We say: Internacional 2-1 Delfin
Given the stakes of Sunday's game, we anticipate a thrilling affair at the Estadio Alfredo Jaconi with both sides going all out in search of the all-important victory. Internacional's home advantage gives them an extra edge and we fancy them to see off Buch's men who have struggled for results on their travels.