I think both Moore and Teahen should be on the 25 man right now.
Teahen should be playing 3d, and Moore left. There's little use to having both DeRosa and Lombo on the 25 man. Teahen could also push Tracy off the roster, since they play the same positions and are LHBs. I've been very skeptical about Moore's long term prospect status due to his history of poor plate discipline, but if you are going to have him on the 40 man, and you have that pit of despair in left, might as well give the hot hand a shot. As they say, if not now, when?