Ahly made their second winter signing after landing German-Brazilian midfielder Hendrik Helmke on a three-and-a-half year deal, the club announced on Friday.
"Helmke's deal takes effect from the first of February," Ahly, who are seeking to equal their own record of winning nine successive Egyptian Premier League titles, said in a statement on their official website.
The 27-year-old, who was born in Germany of Brazilian descent, joined the reigning Egyptian champions on a free transfer after his contract with Norwegian side Tromso expired.
He also played for Malaysia's Sabah FA, Finland's FF Jaro and IFK Mariehamn and German duo VfB Lubeck and Luneburger SK.
Alaa Abdel-Sadek, who is in charge of Ahly's football affairs, said Helmke suffers from a minor knee cartilage complaint and will undergo laparoscopic surgery if needed.
"The player passed a medical but we had some doubts over a minor knee cartilage. We consulted our medical staff who confirmed that it's not serious," Abdel-Sadek said.
"He might only need to undergo laparoscopic surgery that takes 3 weeks to completely heal."
Helmke is the second foreigner to join Ahly in the January transfer window after Nigerian forward Ahly Peter Ebimobowei. They are seeking to bolster their squad after a disappointing first half of the season that saw them fall eight points behind league leaders and arch-rivals Zamalek, who played a game more.
Ahly came from behind to secure a share of spoils in a 1-1 draw against Zamalek in Thursday's Cairo derby.
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