Dacres-Cogley fractured his ankle playing for Crawley Town in their victory at Leyton Orient.
The defender, who had created an initial good impression at Gabriele Cioffi's team, was victim of a late tackle just 16 minutes into what was his third appearance.
He could be sidelined for around three months.
Midfielder Lakin suffered a thigh injury during his debut for Stevenage against Mansfield Town in their 0-0 draw.
Lakin faces several weeks out of action.
In happier news, Michael Luyambula was part of Crawley's Carabao Cup shock against Norwich City.
Luyambula was in goal and kept a clean sheet in the 1-0 Second Round upset.
Former Blues forward Beryly Lubala notched the goal.