Ibehre, who counts Walsall among his former clubs, completed his free transfer from MK Dons on Tuesday, having spent just shy of three months on loan at the club before Christmas during which time he scored four goals in 14 league starts.
Chelsea goalkeeper Walker arrived on loan last week but was denied to chance to make his bow when the U's trip to Hartlepool was postponed.
Anthony Wordsworth will again look to serve the final game of his two-match ban for accruing 10 yellow cards.
Fellow midfielder Kem Izzet (ankle) will once more be assessed along with winger Jack Compton (stomach).
Colchester have lost their last nine successive matches and 12 of their previous 13.