Portsmouth should have two more new faces in their squad for the trip to Colchester.
Boss Michael Appleton, who gave debuts to 11 players in Saturday's 1-1 draw with Bournemouth, is due to bring in winger Jordan Obita on a month's loan from Reading.
And Appleton is also hoping to receive international clearance to sign midfielder Liam Walker in time for the match.
Walker earned himself a trial with Pompey after impressing while playing against them for Gibraltar during the club's pre-season tour of Spain.
It means Appleton's squad is now up to 17, so he will almost be able to fill the substitutes' bench.