No really need, just get cheap cards.
(OPTIONAL) THROW OUT THESE CARDS:
You can throw out two Grim Necromancers for Patches the Pirate and Barnes.
You need finish him by Bloodlust and/or Evolve cards like Dopplegangster or Grim Necromancer.
In turn 6 you can play Doomsayer to skip the sequence with 2/6 Souls, and this is his only use in this deck.
Try to always have that much minions as you can 'cause they can save your ass and finish opponent.
PS.: Check out mine other decks that i used to Beat Lich King!