Dusseldorf are currently 16th in the table and cannot catch 15th-placed Augsburg, meaning that the best that they can hope for is a two-legged relegation playoff to stay in the division.
Securing their spot at this level of football was always going to be the number one priority for Union Berlin this season following their promotion from the second tier last term.
Die Eisernen have impressed many with their performances throughout the season, and they are safe from the threat of relegation, currently occupying 12th position in the table on 38 points.
Indeed, in their first ever campaign at this level, Union Berlin are eight points clear of Dusseldorf heading into the final set of fixtures, having picked up two wins from their last three matches.
Urs Fischer's side were in a spot of bother at the start of June when they drew with Schalke 04 but wins over Koln and Paderborn ensured that they would be present in the 2020-21 Bundesliga campaign.
The situation is more complicated for Dusseldorf as outright survival is beyond the club, meaning that a two-legged relegation playoff against 2. Bundesliga's third-placed side could be on the agenda.
That said, Dusseldorf would be automatically relegated this weekend if they lose against Union Berlin and 17th-placed Wolfsburg collect all three points against Koln.
There is also a scenario where Uwe Rosler's side could draw and still be relegated although that would rely on Werder winning by a four-goal margin in order for the necessary swing in goal difference to occur.
Flingeraner have actually only lost one of their last four in the Bundesliga, picking up points against RB Leipzig and Augsburg in their last two matches.
They have the worst away record in the league this season with just 12 points from 16 matches, though, which is an indication of the size of their task on Saturday afternoon.
Union Berlin Bundesliga form: DLDWWL
Fortuna Dusseldorf Bundesliga form: WLDLDD
Union Berlin will be without the services of their leading goalscorer Sebastian Andersson, with the Swede, who has netted 12 goals this season, unavailable due to a one-game suspension.
Anthony Ujah is expected to get the nod through the middle, but the hosts do have other absentees to contend with as Moritz Nicolas, Sebastian Polter, Christopher Lenz and Julian Ryerson are also absent.
Union Berlin possible starting lineup:
Gikiewicz; Trimmel, Friedrich, Schlotterbeck, Reichel; Gentner, Promel, Andrich; Ingvartsen, Bulter; Ujah
Fortuna Dusseldorf possible starting lineup:
Kastenmeier; Ayhan, Hoffmann, Suttner; Zimmermann, Stoger, Bodzek, Berisha, Thommy; Karaman, Hennings
We say: Union Berlin 1-1 Fortuna Dusseldorf
The pressure is off Union Berlin, but the same cannot be said for Dusseldorf as they look to avoid the possibility of dropping into an automatic relegation spot. We are struggling to separate the two teams, though, and have therefore backed a low-scoring draw in Berlin.