Thiago Alcantara could return ahead of schedule from his muscular injury lay-off, according to Bayern Munich boss Jupp Heynckes.
The Spanish midfielder limped out of Bayern's 2-1 win over Anderlecht in the Champions League in November and has not featured since.
An exact diagnosis of his problem was never revealed by the Bundesliga leaders but Heynckes is now hopeful the 26-year-old will be ready to feature again soon after making good strides in his recovery.
"We need to wait and see over the next two, three weeks with Thiago," Heynckes told a media conference. "It is looking good.
"He has worked phenomenally until now and can already take part in the beginning of [training] sessions.
"[But] one thing is clear, he will not return too early."
Saturday's trip to Mainz was always going to be too soon for Thiago, but Heynckes also has concerns over Sandro Wagner and David Alaba, while Arturo Vidal is definitely out.
"Vidal will miss Mainz with stomach flu," added Heynckes. "Sandro Wagner will probably be involved.
"[Alaba] hurt his pelvis in training yesterday. We will have to see how he feels today."
