The away side, meanwhile, remain in search of a first victory and will be keen to get their campaign up and running with all three points this weekend.
Match preview
Portland Timbers fell to a 1-0 narrow defeat against Houston Dynamo in Sunday's meeting between the sides at the Shell Energy Stadium in Texas.
Phil Neville's men conceded a first-half opener to Aliyu Ibrahim two minutes shy of half time and that was enough to settle a tight affair.
As a result, The Timbers have dropped down to third place in the Western Conference of the MLS table, three points behind division leaders Minnesota United.
Coming up next is the challenge of an opposing outfit who have won both of the last two editions of this fixture after losing the five meetings prior to that.
Having managed just one win from six home matches either side of the new year, Sunday's hosts will need to get going in front of their fans.
Philadelphia Union had to make do with a share of the spoils following a 2-2 draw against Austin FC at the Q2 Stadium on Sunday morning.
Jim Curtin's men opened the scoring through Daniel Gazdag's penalty but soon found themselves after quickfire strikes from Diego Rubio and Jon Gallagher after which Mikael Uhre restored parity.
With just three points amassed from as many games so far, The Zolos sit 13th in the Eastern Conference standings despite having the best goal difference of all bottom-half teams.
Currently on a run of 11 goals let in from their most recent four away involvements, Sunday's visitors will need to keep things tight at the back to stand any chance of success here.
Portland Timbers Major League Soccer form:
L
L
W
D
W
L
Philadelphia Union Major League Soccer form:
W
W
L
D
D
D
Philadelphia Union form (all competitions):
D
D
D
D
L
D
Team News
Portland Timbers' Claudio Bravo is unavailable due to a muscle problem, while defender Marvin Loria continues to battle with a damaged ankle.
The hosts are also set to be without Chile international Felipe Mora, who is set to sit out a fourth straight game on the bounce through injury.
American duo Isaiah LeFlore and Holden Trent are ruled out for Philadelphia Union as they continue to nurse hamstring and knee injuries respectively.
Twenty-three-year-old Leon Flach remains sidelined for the visitors but is making progress towards a potential return to action in the coming weeks.
Portland Timbers possible starting lineup:
Crepeau; Miller, Miller, Zuparic, Mosquera; Chara, Paredes; Antony, Evander, Moreno; Asprilla
Philadelphia Union possible starting lineup:
Blake; Wagner, Lowe, Elliott, Harriel; Martinez, McGlynn, Sullivan, Gazdag; Uhre, Carranza
We say: Portland Timbers 2-1 Philadelphia Union
Goals have been a constant theme of this fixture and we expect this weekend's edition to be no different. That said, we can also see Portland Timbers emerging victorious, albeit by only a narrow margin.