Born in the Anambra State in Nigeria, Mary moved to Cameroon to join AS Fortuna de Mfou Yaoundé's youth team.[3] On 28 March 2012, he was signed by Buriram United in what will be the beginning of three seasons spent in Thai football. His time with Buriram only lasted for a few months before he moved to fourth tier side Bangkok Christian College on 1 August 2012.[4] A move to second tier club Krabi for the 2013 Thai Division 1 League would follow before ending his time in Thailand with fourth tier club Prachuap.
His advisor Ognjen Karisik would bring him to Europe, where he had a trial with Serbian club Vojvodina who signed him on 24 January 2015 on a two-and-a-half-year contract.[5] He made his debut in a Serbian Cup game against Kolubara on 28 October 2015 that ended in a goalless draw, before Vojvodina won 5–4 on penalties.[6] He would see very little playing time with the club after suffering from an anterior cruciate ligament injury. His contract with Vojvodina was eventually terminated, and on 18 July 2016 he signed a one-year deal with Slovenian side Rudar Velenje.[7]