The two sides meet at Signal Iduna Park after facing the league leaders in each of the last two weeks. Mainz shocked Bayern Munich two weeks ago with a 2-1 win while Dortmund held the reigning champions to a 0-0 draw last weekend.
Borussia Dortmund: Thomas Tuchel's men cruised to a 3-0 win over Tottenham in the Europa League in midweek and face a quick turnaround when they lineup on Thursday.
Greek defender Sokratis is back in training and could be in contention to play but the midfield duo of Sven Bender and Ilkay Gündogan are close to a return from a muscular injury and a foot problem respectively but their availability remains unknown.
Projected XI: Bürki; Piszczek, Hummels, Subotic, Durm; Weigl, Gündogan, Schmelzer; Reus, Mkhitaryan, Aubameyang.
Mainz 05: Martin Schmidt watched his side shock Bayern Munich two weeks ago before only managing a 0-0 draw with Darmstadt the following weekend.
The injury list at Mainz is considerably longer than that of Dortmund's but the majority of the players sidelined are close to a return to action. Karim Onisiwo and Sereno are doubts for Sunday's match and Giulio Donati is serving the first of a three-match suspension for a red card.
Projected XI: Karius; Bell, Balogun, Hack, Bussmann; Baumgartlinger, Frei, De Blasis; Malli, Jairo, Cordoba.
Mainz have only managed to beat Dortmund once in their last ten encounters. The win came back in 2014, a 2-0 win at home.
Mainz can move into fourth place with a win on Sunday and Dortmund could close the gap at the top to two points with a victory, with Bayern Munich to have a game in hand.
Both sides have taken points off of the league leaders this season, setting up an enticing match between two of the league's top sides.
Players to Watch
Borussia Dortmund: Pierre-Emerick Aubameyang - The Gabon international has been on fire this season and is second behind Robert Lewandowski for the Bundesliga's top scorer. With 22 goals already this term, it's hard to see the speedy striker slowing down any time soon and he should be the biggest threat posed against Mainz's top four hopes on Sunday.
Mainz 05: Yunus Malli - The midfielder is Mainz's top scorer this season, with ten goals in 25 games. The Turkish international has been one of the main reasons why Martin Schmidt's side are impressing in the Bundesliga and if they want to complete a double over the league's top two teams, they'll need Malli at his very best.