The visitors, meanwhile, saw their unbeaten run of four matches come to an end at the hands of Freiburg last weekend.
Koln, on the other hand, secured only their second win of the season by defeating newly promoted SV Darmstadt 98 away from home last Friday, with David Selke's strike on the hour mark proving enough to claim all three points for his side.
Although the match had all the makings of a relegation scrap with minimal quality on display for the most part, Steffen Baumgart's side produced the more accomplished performance, as they forced opposition goalkeeper Marcel Schuhen into five saves. They also enjoyed more possession despite playing away from home at Stadion am Bollenfalltor, making their win a deserved one in the end.
It was a crucial victory, too, as it moved Koln directly above Darmstadt on goal difference, and outside of the relegation positions in the process. Having collected just one point from their opening seven matches, Baumgart and his players may feel that their season truly began in Darmstadt, and they can now look to begin to climb the table.
Their match against Mainz at RheinEnergieStadion will represent the first of three matches before the upcoming winter break in Germany, with the last of those being against another team currently in the relegation zone in the form of Union Berlin. As such, Koln have clear opportunities to ensure that they do not spend Christmas below the dreaded dotted lines in the table.
Mainz, meanwhile, dropped back into the automatic relegation spots after suffering a disappointing 1-0 defeat at home to Freiburg as towering centre-forward Michael Gregoritsch's 69th minute strike proved the difference between the two sides.
Despite falling to their seventh league loss of the season, interim coach Jan Siewert will likely have been pleased by his side's performance against one of Germany's Europa League representatives. Mainz had 20 shots, 61% possession and 14 corners across the course of an open encounter, but football is often a game of fine margins.
Unfortunately for Die Nullfunfer, they found themselves on the wrong end of those margins once again, but if they can build on that performance - which was probably one of their strongest of the season - then there is every chance that they can escape from danger between now and the end of the campaign.
However, with Koln and VfL Bochum both winning last weekend, Mainz are the last remaining team to only have one victory to their name in the Bundesliga so far this season. Given that they will round off the calendar year with a difficult trip to Borussia Dortmund, there is clear pressure on Siewert to claim at least one win from their upcoming games against Koln and Heidenheim.
Koln will remain without Rasmus Carstensen, Sargis Adamyan and Philipp Pentke due to injury, but Benno Schmitz should be available for selection once again after missing the trip to Darmstadt due to suffering from a cold.
Natural centre-back Luca Kilian deputised out of position in Schmitz's absence, but despite keeping a clean sheet in the important victory, Schmitz is likely to slot back in to provide an outlet. That may be Baumgart's only change to a winning starting XI, with Mark Uth likely to be called upon from the bench at some stage of proceedings.
Mainz, meanwhile, are likely to travel without Edmilson Fernandes, Robin Zentner, Maxim Leitsch, Joshua Guilavogui, Nelson Weiper and Andreas Hanche-Olsen due to injury. Daniel Batz was preferred to Lasse Finn Reiss in goal against Freiburg, and the 32-year-old should keep his place providing Zentner's finger injury keeps him sidelined.
Karim Onisiwo and Jonathan Burkardt both came on during the second half against Freiburg, and Siewert may sense that the timing is right to unleash them from the outset, having been deprived of both for the most part due to their own recent injuries.
FC Koln possible starting lineup:
Schwabe; Schmitz, Hubers, Chabot, Heintz; Ljubicic, Martel; Thielmann, Kainz, Maina; Selke
Mainz 05 possible starting lineup:
Batz; Widmer, Van Den Berg, Caci, Mwene; Krauss, Barreiro; Richter, Burkardt, Onisiwo; Ajorque
We say: FC Koln 1-1 Mainz 05
No team has scored fewer goals than these two sides in the Bundesliga so far this season, meaning we are unlikely to see either goalkeeper troubled on too many occasions at RheinEnergieStadion on Sunday.
With both sides appearing set for relegation battles despite previously enjoying a rise up the table in the last couple of years, we can envisage them sharing the spoils with little to split them in terms of quality.
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