Harris scored against City in the 2 - 2 draw in October at the New Den.
Harris is available for selection tomorrow. Will Lennie give Camerone Jerome a start? Will Harris come straight in? Are we assuming Thorne will start?
I guess we'll find this out on Saturday.
Millwall assistant manager Ray Wilkins told the official Millwall website
"With the players Dennis and I have brought in Neil's chances of starting have been limited. A couple of clubs have come in and been extremely interested in taking Neil on loan, and he has decided that it is in his best interests at the moment to have a spell away.
We have to applaud his attitude in this and hope that during the next month he has an enjoyable and fruitful time at Ninian Park."