United are looking to continue their experiment with Friday night fixtures this term.
Last season United played Wycombe and Oxford in the league on Friday evenings, and also faced Wrexham on a televised FA Cup tie. All three moves proved successful.
Meanwhile, Southend's home clash with the Iron at Roots Hall has also been moved forward 24 hours to Friday March 10, 7.45pm kick-off.
The deadline for club's moving fixtures is Friday.