Born on July 9, 1989, in Barking, England, Coker began his footballing journey at the academy of Queens Park Rangers. He then went on to play for several non-league clubs before signing with Colchester United in 2010. Coker had a successful spell at Colchester, making over 150 appearances for the club. He then went on to play for Southend United, where he became a fan favorite and made over 150 appearances as well.