Zeki arrived at Palace on transfer deadline day in September 2014, but would spend the majority of his first season on loan elsewhere at Rotherham United and Ipswich Town.
The 22-year-old is a product of the Manchester United academy, and made his debut for the Red Devils in a League Cup tie against Leeds United back in September 2011. He went to on appear in the Champions League and Premier League under Sir Alex Ferguson's management, but only made six appearances at Old Trafford during the 2011/12 campaign.
He moved to Belgian club Standard Liege in August 2012 but spent just six months in continental Europe before switching to Tottenham Hotspur in the January transfer window. 2013/14 saw him breakthrough into the Spurs squad, making 16 appearances for the club, including seven during their Europa League campaign.
Despite that the defender, who has also represented England at under-16, under-17 and under-19 levels, was allowed to move to Palace and made two appearances before gaining more experience further down the ladder in the Championship.