Yes. You have to do some dbf editing. Open players.dbf file from your dynasty save folder with DB Commander, find the lines with generated rookies and exchange their names, ratings etc to have Rose or Beasley now in the draft class. Note their IDs. Then open appearance.dbf from the same folder, find lines with those IDs and edit height, weight, skin color, bodytype etc.
If you're not experienced in dbf editing, you should follow those guides while editing:
players.dbf
appearance.dbf
They're for 07, but it's all the same in 08.