Craig Easton, Sofiene Zaaboub, Ryan Hall, Blair Sturrock and Mohsni Bilel, a Tunisian defender, will help new boss Paul Sturrock start to plan ahead for the League Two campaign after he took over a club with only nine registered players.
Southend confirmed last week that they have paid money owed to Her Majesty's Revenue and Customs and Charterhouse Commercial Finance over which they face winding-up and administration hearings.
Sturrock brings his side to Sixfields on September 11.