كتب : Hatem Maher
Ghaddar joined Ahli on a four-year deal after his contract with Bahraini side Al-Shabab expired.
The Red Devils said on their website earlier this week that the 26-year-old would not join the club after undergoing a trial.
However, they had a change of heart after apparently learning that they would not be able to keep hold of Egypt striker Emad Meteb, who moved to Belgian side Standard Liege.
Ghaddar spent one season with Al-Shabab after ending a highly-successful 11-year stint with Lebanese side Nejmeh.
He scored more than 70 goals for Nejmeh to help them to five league titles and five cup triumphs.
Ahli coach Hossam Al-Badri could field him as a lone striker after the likes of Mohamed Fadl, Osama Hosni and Liberian Francis Doe failed to impress in that role.
But they will have to dispense with one of the three foreigners available at their disposal - Angolan winger Gilberto, Algerian playmaker Amir Sayoud and Doe - to make room for the new signing.
Reports suggest that Gilberto, who is confined to the bench after his form faded in recent years, could exit Ahli.
Ghaddar became Ahli's sixth signing in a fruitful summer for the Red Devils.
They landed holding midfielders Hossam Ghaly and Mohamed Shawky, goalkeeper Mahmoud Aboul-Saoud, playmaker Abdul-Hamid Shabana and Egypt forward Geddo.
Ghaddar scores twice in a friendly (the last two goals)