Only Bayern Munich have won this competition more times in its history than Bremen's impressive tally of six, meanwhile, with Florian Kohfeldt hoping to add to that.
Having been in the fourth tier of German football as recently as the 2015-16 campaign, reaching the quarter-final of the German Cup represents a huge success for Jahn.
Managed by their former player Mersad Selimbegovic, who was promoted from his role as assistant manager in 2019, the 38-year-old has done well to stabilise Die Jahnelf in Bundesliga.2, with his side currently eight points clear of relegation in 11th place.
The cup, then, represents the exciting element of Jahn's campaign this time around. Having beaten FC Koln on penalties in the third round, there will be real belief within their ranks that they can spring another upset against a bottom-half Bundesliga side.
After all, had Bremen failed to emerge victorious in their relegation play-off against Heidenheim in July, these two sides would have been competing in the same division this season. While the hosts will rightly begin the game as underdogs, they should have nothing to fear, which makes them a dangerous proposition.
However, Bremen will undoubtedly have gained real confidence from their 2-1 Bundesliga win against high-flying Eintracht Frankfurt on Friday night, with Theodor Gebre Selassie and Joshua Sargent overturning Andre Silva's early strike to gain a crucial three points.
That victory moved Bremen eight points clear of the relegation zone, which should surely be enough of a buffer to stave off any repeat of last season's aforementioned relegation decider.
Instead, Kohfeldt can look to build for the future, with the DFB-Pokal representing a fantastic opportunity of tasting some short-term success. Bremen have a proud history in this competition, with luck seemingly on their side this season having drawn four consecutive sides outside of the Bundesliga.
However, the 38-year-old will be keen to guard against complacency within his ranks ahead of the trip to Regensburg on Tuesday, with progressing to the semi-final far from a formality.
Jahn Regensburg DFB-Pokal form: WWW
Jahn Regensburg form (all competitions): DWDDLW
Werder Bremen DFB-Pokal form: WWW
Werder Bremen form (all competitions): WDWDLW
Jahn will be without Jan Elvedi, who is the brother of fellow central defender Nico at Borussia Monchengladbach, due to suspension.
Sebastian Nachreiner is doubtful due to a muscular problem.
Kohfeldt could opt to help Niclas Fullkrug gain match fitness from the start as he considers shuffling his pack.
Jahn Regensburg possible starting lineup:
Meyer; Saller, Palionis, Kennedy, Beste; George, Gimber, Besuschklow, Stolze; Otto, Caliskaner
Werder Bremen possible starting lineup:
Pavlenka; Veljkovic, Toprak, Friedl; Gebre Selassie, Eggestein, Mbom, Agu; Bittencourt, Osaka; Fullkrug
We say: Jahn Regensburg 1-2 Werder Bremen
We can see a tight, cagey encounter in Regensburg on Tuesday, with both sides involved in a high proportion of draws and close matches this season.
Bremen's extra quality should ultimately tell, though, with the chance of winning the club its seventh DFB-Pokal a major attraction for Kohfeldt and his players.