Rooted in the lower half of the Championship since the start of the campaign, City have been held back by alarming inconsistency.
Only once has Millen's stuttering team mustered a sequence of successive victories - beating Leicester, Sheffield United and Derby during November and December.
Following a 3-1 triumph at Watford on Tuesday night, victory over third-from-bottom Scunthorpe would put distance between City and the drop zone.
"Back-to-back wins at this stage of the season can make a massive difference to our position and that is the challenge that faces us," said Millen. "Beating Watford has given everyone a lift and eased some of the pressure the players have been feeling. Now we have an opportunity to put real distance between ourselves and the bottom three.
"But just because we've had a good win at Watford doesn't mean we're getting carried away. We have been consistent only in our inconsistency this season. I've said all along that Saturday's game is another massive one for us and we have to focus properly on playing well against a Scunthorpe side that will be fighting for their lives."
Source: PA
Source: PA