The hosts remain unbeaten after four matches, but Mainz would overtake their forthcoming opponents in the table should they beat them.
Match preview
Indeed, it has been a dream start to life for Daniel Farke as Gladbach manager, with last weekend's 1-1 draw away to Bayern Munich preserving his unbeaten record since taking over during the summer.
Any side travelling to the Allianz Arena will generally require a few slices of luck in order to come out of the game unscathed, and Die Fohlen were no different last time out, as the Bavarians recorded an astonishing 20 shots on target yet could only breach Yann Sommer's goal once through Leroy Sane's 83rd-minute equaliser.
The Switzerland stopper was inspired on the day, displaying a full range of saves to deny his opponents on countless occasions after Marcus Thuram's smash-and-grab effort had provided Gladbach with a lead to protect after 43 minutes.
The France forward continues to go from strength to strength under Farke's tutelage, having only failed to score in one of his side's first five games of the season. His combination of searing pace and composure in front of goal was evident for all to see as he pounced on Dayot Upamecano's mistake to race in behind Bayern's high line, before coolly slotting the ball beyond the reach of Manuel Neuer.
Farke will hope that his side can quickly revert to a more dominant playing style against Mainz on Sunday after a backs-against-the-wall performance was necessary in Munich, but there is little reason to doubt them on current form.
Mainz, meanwhile, suffered their first defeat of the season with a 3-0 loss at home to Bayer Leverkusen last time out.
Bo Svensson must have fancied his side's chances given that Leverkusen had lost each of their opening three league games of the season - as well as being dumped out of the DFB-Pokal by lowly-ranked SV Elversberg - but Mainz never really got going until it was too late.
Exequiel Palacios's deflected effort gave the visitors the lead a minute before the half-hour mark, with Jeremie Frimpong scoring a rare brace to provide his side with an unlikely three-goal cushion at the half-time interval.
Mainz's hopes of mounting a spectacular comeback after the break were helped by two Leverkusen red cards in the latter stages, but despite creating several decent opportunities, they could not find the first goal back to provide any real momentum.
Svensson will demand that his side defend much better in Monchengladbach on Sunday; if the likes of Moussa Diaby and Frimpong can capitalise on too much space in behind, then Thuram and company certainly can, too, so a more cautious game-plan could be necessary.
Borussia Monchengladbach Bundesliga form:
Borussia Monchengladbach form (all competitions):
Mainz 05 Bundesliga form:
Mainz 05 form (all competitions):
Team News
Gladbach should welcome Ramy Bensebaini back to the side after the left-back missed the draw against Bayern with flu, while Lars Stindl will hope to receive some minutes having been an unused substitute in the last two games following his muscle injury earlier in the campaign.
Alassane Plea was withdrawn with a knock against the Bavarians, but the forward is expected to be fully fit to keep his place coming inside from the left flank.
However, Stefan Lainer is unlikely to be available having only recently returned to training following a thigh issue.
Mainz, meanwhile, will travel without Marcus Ingvartsen due to a knee issue.
Svensson doesn't usually make many changes to his starting XI, with his only real dilemma being whether to start Angelo Fulgini or Lee Jae-sung in the attacking midfield role. He may opt to go with the latter after Fulgini's costly miss against Leverkusen last time out.
Borussia Monchengladbach possible starting lineup:
Sommer; Scally, Itakura, Elvedi, Bensebaini; Kone, Kramer, Neuhaus; Hofmann, Thuram, Plea
Mainz 05 possible starting lineup:
Zentner; Bell, Hack, Leitsch; Widmer, Kohr, Stach, Aaron; Lee; Burkardt, Onisiwo
We say: Borussia Monchengladbach 3-1 Mainz 05
Although Mainz have won both of their away games this season, we expect Gladbach to record another victory on Sunday.
Die Fohlen have hugely improved under Farke's management so far and they clearly have the more talented individuals to gain a win; providing they perform on the day, of course.