McGreal takes his side to Sussex.
Should the match be level over ninety minutes, then the game will go to a penalty shoot out, giving both sides a chance to pick up an additional point.
The U's will face fellow League Two side Crawley in the first of three group games at this stage of the new look competition.
Colchester United head to Crawley on Tuesday night, as they get their Checkatrade Trophy journey underway.
U's: Walker, Barnes, Vincent-Young, Brindley, Eastman, Wynter, Peter, James, Kinsella, Lapslie, Diaz Wright, Szmodics, Dickenson, Drey Wright, Sembie-Ferris, Porter, Bonne, Johnstone
It's Peter's first trip with the first team, and he will wear squad number 40.
The U's have named a strong squad for the trip to the Checkatrade Stadium, with U23s Dexter Peter, Cameron James and Diaz Wright all making the trip to Sussex for the 7.45pm kick-off.
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