Bilel Mohsni and Adam Bouzid have failed to get international clearance in time for today's match against Stockport County.
That means the duo will be ineligible for this afternoon's npower League Two clash.
It is expected that United will receive clearance early next week from the French Football Federation and Moroccan FA.
Meanwhile, Blues boss Paul Sturrock will hand Southend debuts to 9 of his starting 11 against the Hatters.
Glenn Morris, Sean Clohessy, Josh Simpson, Craig Easton, Barry Corr, Mark Phillips, Luke Prosser, Louie Soares and Chris Barker.
Ryan Hall (suspended) and Peter Gilbert (injured) miss out.
Southend: Glenn Morris, Sean Clohessy, Josh Simpson, Anthony Grant, Craig Easton, Barry Corr, Mark Phillips, Luke Prosser, Louie Soares, Chris Barker, Scott Spencer.
Subs: Graham Coughlan, Matt Paterson, Sofiene Zaaboub, Johnny Herd, Harry Crawford, Blair Sturrock, Rhys Evans.
Stockport: Owen Fon Williams, Mark Lynch, Robbie Williams, Paul Turnbull, Danny Swailes, Mansour Assoumani, Greg Tansey, Barry Conlon, George Donnell, Adam Griffin, David Poole.
Subs: James Vincent, Richie Partridge, Danny Pilkington, Andy Halls, Danny Rowe, Tom Fisher, Ian Ormson.
