Xabi Alonso's men play a top-flight side for the first time in the cup this year, while the visitors dispatched Union Berlin and Borussia Dortmund in the second round and round of 16, respectively.
Match preview
Observers are curious to see Bayer Leverkusen's approach for Tuesday's Pokal clash with Stuttgart, with Alonso's men keen to preserve their season-long undefeated run that was extended to 29 games after Saturday's 2-0 league victory over Darmstadt.
Nathan Tella impressively netted twice for the Bundesliga leaders, who kept a two-point lead over Bayer Munich before hosting Thomas Tuchel's men on February 10.
The importance of that top-of-the-table encounter has observers monitoring how Alonso navigates a potentially pivotal week in which they could exit the domestic cup and lose their marginal advantage in the Bundesliga if it goes badly.
With Bayern having the week to prepare for that clash, it remains to be seen how the Bayer boss approaches Tuesday's cup clash with Stuttgart, with Die Werkself hoping to maintain their challenge for a first Pokal title since their maiden one in the 1992-93 season.
The domestic cup ranks lowest on the list of Bayer's priorities this term, suggesting changes could be in the offing for Alonso's men, who have a crucial league meeting with Die Bayern a few days later.
Stuttgart travel to Leverkusen after back-to-back wins in the Bundesliga, having lost three of their previous four league encounters.
Saturday's win at Freiburg ended a run of three consecutive away losses for Sebastian Hoeness' troops, who hope to carry that confidence of road success into their meeting against their unbeaten hosts.
Unlike Bayer, Stuttgart have claimed more than one Pokal title, even if the last of their three triumphs came in 1997, and they seek a first podium finish in 11 years, seven before Leverkusen ended as runners-up in 2020.
However, Hoeness' men are two wins away from dreaming of another final, even if their adeptness at defeating Bundesliga clubs in Union Berlin and Dortmund should give the away side confidence against the highest-ranked side in the competition.
Stuttgart have navigated three rounds against Balingen, Union and BVB, scoring seven times and conceding none, standing them in good stead against Bayer on Tuesday as they seek to sow a seed of doubt into Alonso's men before the latter face Bayern.
Bayer Leverkusen DFB-Pokal form:
W
W
W
Bayer Leverkusen form (all competitions):
W
W
W
W
D
W
Stuttgart DFB-Pokal form:
W
W
W
Stuttgart form (all competitions):
L
W
L
L
W
W
Team News
Edmond Tapsoba featured for the first time since returning from Burkina Faso duty at AFCON 2023, and the centre-back should start for Leverkusen on Tuesday.
However, Odilon Kossounou is unavailable for another week, with Ivory Coast progressing to the competition's semi-finals despite the defender's disastrous 44 minutes that saw him dismissed against Mali.
Injury absentees — Victor Boniface (groin), Exequiel Palacios (thigh) and Arthur (tendon) — are not expected to play any part in the quarter-final tie.
As for Stuttgart, in-form Denis Undav should start with the Brighton & Hove Albion loanee scoring four times in the last two league fixtures, including netting his first Bundesliga hat-trick in the 5-2 win over RB Leipzig.
It remains to be seen if Serhou Guirassy features in any capacity, having returned from Cup of Nations duty with Guinea.
Absent are Silas Katompa Mvumpa, featuring for AFCON semi-finalists DR Congo, South Korea's Woo-yeong Jeong (Asian Cup) and the injured Dan-Axel Zagadou and Nikolas Nartey, both of whom are nursing knee injuries.
Bayer Leverkusen possible starting lineup:
Kovar; Stanisic, Tah, Tapsoba; Tella, Andrich, Xhaka, Grimaldo; Hofmann, Hlozek; Schick
Stuttgart possible starting lineup:
Nubel; Stergiou, Anton, Rouault; Vagnoman, Karazor, Stiller, Mittelstadt; Millot, Fuhrich; Undav