The home team have made an excellent start in 2024-25, and are first with 15 points from five games in the Regionalliga Northeast division, while the visitors are fourth with three points from one game in the Bundesliga.
Match preview
The hosts were relegated to the fourth tier of German football at the end of 2019-20, and after narrowly missing out on promotion in 2021-22 and 2022-23, they will hope to finish first and claim the division's only promotion spot this campaign.
After just five games, Carl Zeiss Jena are already four points clear of second-placed Lokomotive Leipzig, and are also the league's top scorers having netted 17 times.
FCC have only kept one clean sheet in their five league games so far, although they have only conceded the first goal once.
Manager Henning Burger's side won 4-1 last time out against Plauen on August 24, and have won 10 and drawn four of their last 14 competitive matches.
However, Burger will be aware that his team have failed to progress from 10 of their last 11 ties in the DFB-Pokal.
Opponents Bayer Leverkusen come into the clash off the back of a thrilling victory in their opening Bundesliga game of the season against Borussia Monchengladbach on August 23.
Alonso's side had taken a two-goal lead in the first half thanks to goals from Granit Xhaka and Florian Wirtz, but Nico Elvedi halved Die Fohlen's deficit in the 59th minute, before Tim Kleindienst levelled the scoreline on the 85th minute.
It seemed as if Leverkusen would begin their title defence with a disappointing draw, but in typical fashion, Die Schwarzroten and Wirtz managed to find a winner in the 11th minute of stoppage time.
While the visitors have not performed as well as they could have in either their Bundesliga opener or the German Super Cup final against Stuttgart on August 17, Alonso will take confidence from the fact his side have continued to display their resilience in difficult moments.
In 2023-24, Leverkusen won the DFB-Pokal after beating second-tier side Kaiserslautern 1-0 in the final on May 25.
Die Schwarzroten have also progressed from 20 of their last 24 away matches in the competition, including their three most recent games on the road.
Carl Zeiss Jena form (all competitions):
Bayer Leverkusen form (all competitions):
Team News
Carl Zeiss Jena will be without Maurice Hehne, Marcel Hoppe, Elias Loder, Justin Petermann and Justin Smyla.
The hosts could name a similar lineup to the one that beat Plauen last time out, so expect goalkeeper Marius Liesegang to be shielded by a defence of Nils Butzen, Soren-Kurt Reddemann, Khalid Abu El Haija and Paul Kramer.
As for the visitors, Alonso is certain to make a number of changes, with the likes of Wirtz, Jeremie Frimpong and Piero Hincapie all potentially dropping out of the side that beat Borussia Monchengladbach.
However, Leverkusen will not be able to select Viktor Boniface, Odilon Kossounou or Martin Terrier due to suspension, while Exequiel Palacios is out because of a knee injury.
Carl Zeiss Jena possible starting lineup:
Liesegang; Butzen, El Haija, Reddemann, Kramer; Gipson, Muqaj, Schau, Richter; Weinhauer, Sezer
Bayer Leverkusen possible starting lineup:
Kovar; Tapsoba, Tah, Belocian; Tella, Andrich, Garcia, Arthur; Hofmann, Adli; Schick
We say: Carl Zeiss Jena 2-5 Bayer Leverkusen
Regardless of the changes that Leverkusen make, their squad is strong enough to overcome their fourth-tier opponents, and they should be clear favourites in Wednesday's clash.