Roche sustained a thigh injury in the first half of the Shrimps' victory over Southend last Saturday and is facing up to a fortnight on the sidelines.
Joe Anyon was signed on loan in time for the midweek defeat at Bury and looks certain to line up between the posts again, despite a mistake on his debut.
Anyon let a Lennell John-Lewis shot squirm under his hands with just five minutes remaining, and McIlroy said: "They only really had one shot on target throughout the game and unfortunately Joe let it through.
"I feel for the boy and we will now just have to forget it and move on to Saturday and work hard again."
Defender Paul Scott is stepping up his fitness but is set to remain absent as he recovers from a knee operation.
Source: PA
Source: PA