While the hosts sit ninth in the Western Conference with 25 points from 20 matches, the visitors languish at the bottom of the Eastern Conference with 18 points from 19 games played.
Match preview
By last season's standards, when they finished second in their conference, Seattle Sounders are enduring a disappointing season, as a 12-point gap already separates them from the top three sides in the Western Conference.
However, they have shown signs of improvement in the last three matches, posting two wins and a draw, even keeping a clean sheet in one of those encounters.
The dramatic late turnaround in their last outing against Dallas could serve as a real boost for their season, as former Swansea loanee Jordan Morris bagged a brace, scoring in the 88th and 94th minutes, snatching victory from the jaws of defeat for Seattle.
Brian Schmetzer's men have not managed to win back-to-back MLS matches this season, and this will be their target when they welcome an out-of-sorts Chicago Fire to Lumen Field.
The hosts boast an unbeaten home record in this fixture, having secured seven wins and two draws in the nine times they have hosted this matchup, which will undoubtedly give them a significant confidence boost ahead of Sunday.
Chicago Fire appeared to be gaining some momentum in recent weeks, putting together a four-match unbeaten run, but this streak was snapped by a 4-2 defeat at Orlando last Saturday.
Having missed out on the playoffs last year with a 13th-place finish in the Eastern Conference (falling short by three points), the Men in Red would have hoped for a better showing this season, but things are shaping up to be even worse.
Frank Klopas's side have particularly struggled on the road, picking up just one win in nine away matches - notably, this was an impressive 4-1 victory at Toronto on June 16.
Playing three consecutive away fixtures was always going to be a tough ask for Chicago, and while a win and a defeat in the first two were not disastrous, another loss on Sunday could make things dire.
Seattle Sounders Major League Soccer form:
W
D
L
W
D
W
Chicago Fire Major League Soccer form:
L
D
D
W
W
L
Team News
Seattle Sounders will be without defender Jon Bell who is away with the Jamaican national team at the ongoing Copa America.
Alex Roldan is also going to miss this clash as he has a head injury that has kept him sidelined for several weeks.
Argentine winger Pedro de la Vega, who has not featured for the Sounders since May, is also questionable as he is carrying a hamstring injury.
For the visitors, they will remain without Swiss attacker Xherdan Shaqiri, who is away on international duty.
Chase Gasper, Andrew Gutman and Tobias Salquist all have leg injuries and are sidelined, while Federico Navarro's fitness is questionable.
Seattle Sounders possible starting lineup:
Jung; Segawa, Jesiel, Ominami, Sasaki; Yamamoto, Tachibanada, Tono; Ienaga, Marcinho, Kobayashi
Chicago Fire possible starting lineup:
Osako; Shiotani, Nakano, Higashi; Arai, T. Matsumoto, H. Matsumoto, Shichi; Ohashi, Sotiriou, Kato
We say: Seattle Sounders 2-1 Chicago Fire
Heading into this fixture, both history and momentum favors the hosts, which is why we think they will extend their dominance on home soil on Sunday.