The 17-year-old midfielder completed his first individual session on Monday, beginning the next stage of his recovery after an extended absence.
Eichhorn joined Bayer Leverkusen from Hertha BSC during the summer but was diagnosed with a metabolic disorder following medical examinations. The condition required treatment and forced him to put his football career on hold.
His return to the pitch is an encouraging development for the club, although there is no confirmed timetable for his return to full team training.
Sporting director Simon Rolfes welcomed the youngster’s progress but stressed that Leverkusen would take a careful approach.
“We are delighted Kennet is back and can train individually on the pitch,” Rolfes said.
“We will support his recovery step by step and monitor his progress closely. There is currently no specific timeframe for his return to full training.”
Eichhorn will continue his rehabilitation in Leverkusen as the club gradually assesses his progress. Reports suggest he could potentially be integrated into team training next week, but that remains dependent on his recovery and has not been confirmed by the club.
Leverkusen will therefore avoid putting a deadline on his comeback as the highly-rated teenager works towards a return to competitive football.