Werder Bremen, chasing a Europa League spot, will have three key players back for their home game against relegation-threatened Mainz 05 on Saturday, including top scorer Claudio Pizarro, who sat out a suspension.
Starting keeper Tim Weise and Philipp Bargfrede are fit, returning to training this week after minor injuries. Bremen are in sixth place on 40 points.
Schalke 04 will be without their starting goalkeeper, Timo Hildebrand, for their game at Hoffenheim on Sunday after he picked up an elbow injury in their Europa League 4-2 defeat to Athletic Bilbao on Thursday, the club said.
Former Germany international Hildebrand, who joined in October as a replacement for injured Ralf Faehrmann, will be out for an unspecified period of time. Schalke, in third place on 53 points, are in the running for a Champions League spot.
The Bundesliga season should end in a final four of the league's top teams with the champions then crowned in a final game to make it more exciting, Bayer Leverkusen boss Wolfgang Holzhaeuser said in the club's stadium magazine.
"My dream always is to have a real final stage with the top four teams fighting for the title; real highlights with semi-finals and a final.
"The football decision-makers should give up their conservative position and search for better solutions and then show the courage to change things," Holzhaeuser wrote.
Fifth-placed Leverkusen host Freiburg, who are 13th, on Saturday.
