Bundesliga Preview: Leverkusen v Dortmund
In a scenario that few could have envisaged just six months ago, Dortmund - who have finished in the top two for the last four seasons, including championship-winning campaigns in 2010-11 and 2011-12 - start the year trapped in the relegation zone.
Jurgen Klopp's men have won just four of 17 league fixtures and a wretched record away from home, which has seen them collect four from a possible 27 points, has left them fighting to avoid the drop.
Dortmund's miserable league form becomes an even greater mystery when taking their excellent performances in the UEFFA Champions League into consideration, but defender Mats Hummels said the squad has looked good in a mid-season training camp in La Manga.
"Apart from the injuries some players suffered, we've all worked very well," Hummels told Dortmund's official website.
"We all seem to be in good shape which is vital to be successful in the Bundesliga and the other competitions.
"I'm in a much better shape than in the first half of the season. In the 90 minutes against Utrecht [friendly] I felt, despite the tough training sessions before, in top shape. I felt better than in any of the games in the first half of the season and that's an important step.
"Competitive matches are a whole different ball game. You just never know for sure."
Sebastian Kehl (shoulder) was injured during training, while Sven Bender (knee) seems set to continue on the sidelines, but Kevin Grosskreutz should recover from a knock.
Australian goalkeeper Mitchell Langerak is still absent on international duty and, while Japan have been knocked out of the Asian Cup, it remains to be seen whether Shinji Kagawa will be drafted straight into Klopp's squad.
Gabon striker Pierre-Emerick Aubameyang's participation is also doubtful, despite their elimination from the Africa Cup of Nations earlier this week.
But the fact that the Asian Cup is still to be complete may be a blessing for Dortmund, as it robs Leverkusen of two of their main attacking threats.
Australia's Robbie Kruse and South Korea's Son Heung-min are both set to play in Saturday's final in Sydney.
New Dortmund signing Kevin Kampl, who joined from Red Bull Salzburg, may get the chance to feature against the club where he began his career.
Roger Schmidt's side went to the United States for their training camp and more recently beat Mainz 4-1 in a friendly with Stefan Kiessling, Gonzalo Castro, Josip Drmic and Emir Spahic on the scoresheet.
Leverkusen, who sit third in the table but are already 17 points behind leaders Bayern Munich, had defender Tin Jedvaj sign a permanent deal this week, keeping him at the club until 2020.
Jedvaj is expected to miss this clash through injury, though, as Leverkusen look to end a poor home record against Dortmund.
Dortmund have not lost in their last seven trips to the BayArena and that is sure to give Klopp's side confidence.
But goals from Karim Bellarabi and Kiessling gave Leverkusen a 2-0 win at Signal-Iduna Park earlier this season.