Triple blow for U's
Colchester will be without on-loan trio Jeffrey Monakana, Elliot Lee and Cian Bolger for their FA Cup first-round tie at home to Sheffield United.
Preston winger Monakana, West Ham striker Lee and Bolton centre-back Bolger have all been denied permission to feature by their respective parent clubs.
However, goalkeeper Sam Walker and defender Luke Garbutt, on loan from Chelsea and Everton respectively, have been cleared for involvement.
Defender Tom Eastman makes a timely return to full fitness following his ankle injury to boost the ranks, while boss Joe Dunne may also be strengthened by the return of one or two more from the treatment room.
Sheffield United striker Shaun Miller is poised for his first start since Boxing Day.
Miller made his comeback off the bench in last month's home win over Port Vale and has appeared as a second-half substitute in the last two matches following long-term knee ligament damage.
But the Blades will be without suspended winger Febian Brandy, who starts a four-game ban following his dismissal in last week's defeat at Shrewsbury - his second red card of the season.
On-loan pair Simon Lappin (Cardiff) and Conor Coady (Everton) have been given permission to play by their parent clubs, while the Blades are hoping Leeds defender/winger Aidy White is also available.