Sheffield Wednesday defender Rob Jones is hoping to shake off concussion.
Jones, signed on loan until the end of the season from Scunthorpe two weeks ago, banged his head while scoring for the Owls in their 3-1 midweek defeat to Brentford.
Jones was forced off shortly after and taken to hospital but has not been ruled out this weekend and manager Gary Megson is prepared to give him until the last possible moment before making his decision.
Should Jones fail to make it his replacement on Tuesday night, Jon Otsemobor, could continue, while Michael Morrison provides Megson with an alternative option.
Megson, who has no other new injury or suspension worries, is also waiting on the availability of midfielder Giles Coke, who has missed the last two games due to tonsilitis.
Winger Jermaine Johnson may have played his way back into the starting line-up after stepping off the bench in midweek. The Owls, four points above the relegation zone, are chasing their first win in six matches.
Tommy Smith returns to the Colchester squad.
The on-loan Ipswich defender has missed the last two matches as he was on international duty with New Zealand.
Smith may struggle to reclaim his place in the side, however, after the Us registered back-to-back wins in his absence, including a 5-1 hammering of Exeter, to maintain their faint play-off hopes.
Fellow centre-halves Pat Baldwin and Magnus Okuonghae remain long-term absentees.
Baldwin is still some way from a return to action due to an Achilles problem and Okuonghae is out for the season following ankle surgery.
Midfielder John-Joe O'Toole should be involved again after playing 90 minutes for the reserves in midweek to build up his fitness after a cruciate injury.
