Goalkeeper Logan has penned a six month loan deal but is unavailable for the clash with his parent club Leicester in the Carling cup.
Boss Andy Scott told themillers.co.uk he was pleased to land his latest target, who has been promoted from this division previously with Stockport..
"Conrad has experience of getting promoted from this division and that is vital. We have got a few lads that have come in now that have been promoted from this league so they know what it is about.
"Leicester rate Conrad very highly but credit to the lad, he wants to get out and play games. He went to Bristol Rovers last year and nearly kept them up, so he will come in and add more competition to that position." said the gaffer.