The 17-year-old midfielder has been working individually after being sidelined by a metabolic disorder. According to Bild, the aim is for him to be fully fit when the squad resumes preparations after the winter break. The newspaper added that any earlier return would be regarded as a bonus.
Eichhorn has already taken an important step by returning to the training ground. Bayer Leverkusen confirmed on 2 November that he had completed his first individual session and would continue his rehabilitation programme at the club.
Sporting director Simon Rolfes welcomed his return but stressed that there was no fixed timetable for a return to full team training. Leverkusen intend to monitor his progress closely and increase his workload gradually rather than risk putting pressure on the youngster.
The illness followed a difficult summer for Eichhorn. After suffering a severe gastrointestinal virus and losing weight, he was diagnosed with a metabolic condition that required hospital treatment and kept him away from football for several months.
Leverkusen signed him from Hertha Berlin in the summer for a reported €9 million after he emerged as one of the most highly rated young midfielders in Germany. His absence has meant that the club have had to be patient with a player they regard as a significant long-term prospect.
During recent weeks, he prepared for his return with a private trainer, working in coordination with Leverkusen as he rebuilt his strength following treatment. His physical condition is being monitored closely, and the club are avoiding unnecessary pressure.
The immediate priority is therefore not to accelerate his return for a particular match. Bild's report makes clear that the winter-break target is a goal rather than a confirmed date, while Leverkusen's public position remains that his recovery will be managed step by step.
For Eichhorn, being back on the pitch is already progress. The next stage will be building up his strength and conditioning until he can rejoin full team training without jeopardising his recovery.