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The 31-year-old midfielder joins from Belgian club Royal Antwerp. Al Jazira announced the signing on their official website.
"Al Jazira Football Company completed the signing of the Cameroonian midfielder Sebastien Siani, the former player of Anderlecht and Antwerp, and the African Cup of Nations winner in 2017. He joined the first football team of Al Jazira as soon as the preparations for the upcoming season starts," the club said in a statement.
"Siani has passed all the medical tests and he joined his new teammates in Al Jazira in their preparations for the upcoming season 2018 - 2019," the statement added.
Siani is Al Jazira's second signing after the club had captured Ghanaian winger Ernest Asante from Danish club FC Nordsjaelland. The club will be led by a new manager in Dutchman Marcel Keizer, who replaced countryman Henk ten Cate.
Siani graduated from the Kadji Sports Academy in 2004, an academy where former FC Barcelona, Inter Milan, Chelsea and Everton striker Samuel Eto'o played in his youth.
Siani began his professional career with Union Douala before making the big move to Belgian club Anderlecht in 2006.
Siani was then loaned out to Zulte Waregem, Union SG and Sint-Truiden. After his loan spells, Siani moved to FC Brussels. He then spent five seasons with KV Oostende, where he made 167 appearances and scored 22 goals.
Capped 22 times by Cameroon, Siani won the African Cup of Nations in 2017, providing the assist as Vincent Aboubakar scored the match-winner in the Indomitable Lions' 2-1 victory over Egypt.
Al Jazira, who won their second AGL title in the 2016-17 season, were unable to defend the title, finishing seventh last season.
james@khaleejtimes.com
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