Following his release by Ipswich Town, Gerken re-signed for his first club Colchester United on 13 July 2019 on a free transfer. He made his return debut on 3 August in their 1–1 League Two draw with Port Vale.
Following his release from Ipswich Town, Gerken returned to Colchester United on a free transfer on July 13, 2019. His return debut was on August 3rd in their 1–1 League Two match against Port Vale.