Spinner, who now lives in Australia, made 245 appearances for the Blues during two successful periods in the side which included four promotions.
And he has now been rewarded with a game in aid of Little Havens Children's Hospice against another of his old teams, Derby County, at Roots Hall on Tuesday May 5.
Prior told the official site: "I am really looking forward to coming back to England and seeing everybody again. I am a Southend boy and I am really proud of my time with Blues. It's great that the game is also against one of my old teams as I also remember my spell at Derby fondly. I made many friends there and I feel proud to have been a part of a wonderful side. Hopefully we can raise a lot of money for Little Havens, a charity I am very passionate about."
Tickets for this match are now on sale from the Southend ticket office priced at £10 for adults/seniors/students and £2 for children.
At present, only the Southend Echo East Stand is open for the game.
A number of hospitality and sponsorship packages are also available.
For further details contact the club's commercial department on 01702 304133.