Çelik played for IF Warta and BK Häcken at youth level before joining GAIS in 2007. "I started as a striker but now I play as an inner midfielder and winger. It does not matter if I play on the right or the left, both positions work for me," he said in an interview on the club's website. Çelik made his competitive début against GIF Sundsvall in the Allsvenskan on 20 July 2008, and appeared in the starting eleven for the first time six weeks later against IFK Göteborg. He signed a three-year contract in May 2009, and scored his first goal for the club later that year against Kalmar FF.