The keeper was released by Coventry City manager Chris Coleman last season after playing for the Sky Blues for three years.
"I have spoken to three clubs, two in the Championship and one in League One and hope to firm things up later this week when their managers are back from their holidays," said Marshall to the CT.
"Three have shown serious interest in me with the possibility of being first choice at a Championship and League One side and competing for a place at another Championship club.
"Location is a big factor for me and my family this time and I am looking to move nearer London. 
"My little girl is getting near to school age and so we want to get her settled.
"I have also got a couple of business interests outside of football and it would be helpful for me to be near the capital to continue with those.
"I have started taking my coaching badges but none of the roles at the clubs I have spoken to involve any coaching, but I am certainly keeping my options open to go down that route in the future. Chris Coleman has told me I am a good coach and it is something I enjoy."
All at Covsupport News Service wish Andy well