Charlton will check on goalkeeper Ben Hamer.
Hamer had to come off 20 minutes from the end of Saturday's 1-0 win at Bournemouth after twisting his ankle.
John Sullivan replaced Hamer at Dean Court and will be in the starting line-up if the Addicks' regular number one fails a late fitness test.
Manager Chris Powell named an unchanged line-up at the weekend and must decide whether anyone needs a rest.
The back four is likely to stay the same but the likes of Bradley Pritchard and Darel Russell are pushing for places in midfield while Leon Clarke and the fit-again Danny Haynes (hamstring) could be drafted in up front if Powell makes changes.
Colchester are likely to remain unchanged for their daunting trip to the runaway League One leaders.
The U's brushed Preston aside 3-0 in impressive fashion on Saturday to clinch a first league double of the season and manager John Ward will be hard pushed to make any changes.
Skipper Kem Izzet overcame an ankle injury to start against North End, making his 400th league appearance for the Essex club.
Tom Eastman also lined up at the heart of defence despite having needed stitches to a head wound sustained at Oldham in midweek.
Colchester are unbeaten in three and have tasted defeat just once in their previous six but they face a tall order against the Addicks, who are undefeated in 10 matches and have not lost in the league at The Valley this season.