Former U's midfielder and assistant boss back in football in Ireland.
Mark, who left his role as assistant boss at the Weston Homes Community Stadium at the start of September, has been named as assistant manager at top flight Irish side Drogheda United.
He will be number two to new United boss John McDonnell.
Talking to the Irish Herald, Mark said: "After I left the last job I had, Colchester United, I made the decision to come home to Ireland see if I could get some work over here.
"And then the chance came to go in to Drogheda as John's assistant. I had watched a bit of League of Ireland at the tail end of last season, so I had an idea of the standard.