Mainz suffered a blow to their European hopes last week while Schalke boosted their hopes of survival.
Match preview
Last weekend's 3-0 defeat against Wolfsburg ended Mainz's 10-game unbeaten streak, and dented their hopes of finishing in the top six.
Drawing a blank was also a rare occurrence for Bo Svensson's side, as it was the first time they have failed to score in a game since before the World Cup - against their upcoming opponents back in November.
The underwhelming performance was in big contrast to their 3-1 win over reigning champions Bayern Munich a week earlier.
With there being a 50/50 chance that seventh will not open up a European spot due to the potential outcome of the DFB-Pokal final, Mainz need to return to winning ways here to put the pressure on the sides above them.
Their superb run of 22 points from a possible 30 places them in a position where they are just three points behind Bayer Leverkusen in sixth with four games to go.
This will be marked down as a must-win game though, given that they have a tricky run to the line to finish the season, with Eintracht Frankfurt and Borussia Dortmund away to come.
Despite Schalke's recent troubles though, Mainz have a notoriously poor record over them, winning just three of their 12 meetings at home.
That may give the visitors some much needed belief as they aim to avoid the drop after being in a perilous position not long ago.
Schalke sealed back-to-back home wins for the first time this season with a 2-1 win over Werder Bremen last weekend.
Coming from behind for a vital three points thanks to goals in the final 10 minutes from Sepp van den Berg and Dominick Drexler could be huge, considering they were staring defeat in the face.
However, their away form is the big reason why they find themselves in trouble, as the side have won just one of their 14 away games this season.
With just four points separating 13th and 17th in the Bundesliga though, any points could be pivotal.
The away form is an issue for Thomas Reis's side though, as they have lost their last two on the road, both without scoring.
Mainz 05 Bundesliga form:
D
W
D
D
W
L
Schalke 04 Bundesliga form:
D
L
L
W
L
W
Team News
Silvan Widmer was forced off in the defeat against Wolfsburg last weekend with an ankle injury and is set to miss out for Mainz here.
Jonathan Burkardt is the other absentee for the hosts, as his knee injury has kept him out for the whole of 2023.
Moritz Jens is a doubt for Schalke as he recovers from a thigh injury, while fellow defender Cedric Brunner continues to nurse a shoulder injury.
Tim Skarke is close to a return after an ankle injury, but Reis will be without Soichiro Kozuki, Justin Heekeren and Eder Balanta here.
Mainz 05 possible starting lineup:
Zentner; Hanche-Olsen, Bell, Fernandes; Da Costa, Barreiro Martins, Kohr, Caci; Onisiwo, Ajorque, Lee Jae-sung
Schalke 04 possible starting lineup:
Schwolow; Matriciani, Yoshida, Kaminski, Uronen; Kral, Krauss, Drexler; Karaman, Terodde, Bulter
We say: Mainz 05 1-0 Schalke 04
Mainz will be looking for an immediate response after last week's disappointment, but may not find it easy against a side fighting for their lives.