Illness cannot slow down Borussia Dortmund. Ilkay Gündogan and Roman Weidenfeller had to miss Thursday's Europa League encounter with Porto after falling sick, but that did not stop the yellow and blacks from taking a commanding lead in the tie. Their feverish fixture list will not let up, though, as they travel to Leverkusen for a big match Sunday.

Thomas Tuchel is more likely to cook up a remedy to Dortmund's packed schedule now that he has healthy midfielders to call upon. Nuri Sahin returned after a year-long injury layoff to put in a solid hour for Dortmund on Thursday. Tuchel also has Gonzalo Castro at his disposal after leaving the midfielder out of the squad in midweek.

Dortmund's task may be made a tad easier by Javier Hernandez's absence. Leverkusen are still searching for the correct solution in attack without the Mexican. They struggled to beat Darmstadt after Werder Bremen knocked them out of the German Cup last week, and ground out anotherone-goal win in the Europa League. Stefan Kiessling has been a different player trying to lead the line on his own, and has yet to score this season without "Chicharito" at his side.

The fixtures between these two clubs have been tight in the recent past. Leverkusen have the more success with two wins, two draws, and a loss in their last five encounters. Dortmund did, however, hand them a 3-0 drubbing in their most recent meeting last September.

Leverkusen will hope that striker Pierre-Emerick Aubameyang's inconsistent showings in recent weeks may prevent such a performance this time around.

The derby between Cologne and Gladbach is set to be fiesty once again

Fiery Rhine derby expected in Gladbach

Just as it was last season when the Cologne fans stormed the pitch, this Rhine river derby will be a heated affair. Cologne fans are expected to hold a demonstration before the game, but the match itself should be a display worth watching. Only three points separate Gladbach from Cologne in the Bundesliga table, setting the stage for an early six-pointer for in their respective hunts for a European place.

"I am excited for a match with such big emotions," coach Andre Schubert said on Thursday.

Cologne's defense has been able to handle most of the opposing attacks thrown at them this season, mainly due to Peter Stöger's conservative tactics. Part of his new formula is playing Jonas Hector in midfield, a move Stöger believes has helped the team's organization in recent weeks.

"Because of his understanding of the game, Jonas is a player who has mastered all the positions on which organization and build-up play are based ," Stöger said.

Hector's presence in the middle will be important to slow down Gladbach's impressive attack. With Lars Stindl and Raffael leading the charge, the Foals' front line has remained one of the best in the Bundesliga - only Dortmund and Bayern Munich have scored more goals. Defense is where they have been the most inconsistent, and with Martin Hinteregger and Martin Stranzl expected to miss the match, they may have a hard time collecting their first clean sheet in 2016. Gladbach have just one win in the new year, and they will need another good result if they want to build on their Bundesliga resurgence from the first half of the season.

Matchday 22 fixtures:

Eintracht Frankfurt vs. Hamburg (Friday)

Bayern Munich vs. Darmstadt (Saturday)

Borussia Mönchengladbach vs. Cologne

Hertha Berlin vs. Wolfsburg

Hoffenheim vs. Mainz

Ingolstadt vs. Werder Bremen

Bayer Leverkusen vs. Borussia Dortmund (Sunday afternoon)

Schalke vs. Stuttgart (Sunday evening)

Hannover vs. Augsburg