Can I play a card with 0 cost in marshalling phase when I am not the active player?

I know that I cannot play cards with gold cost in the marshalling phase, but how about 0 cost cards? How about first reduce cost to 0 then play?

"Only 1 player can marshal cards (i.e., play cards from his hand to the play area by paying the printed gold cost on the card) at a time, but other players can still take “Marshalling:” or “Any Phase:” actions as usual."

Cards with a gold cost of 0 still count as having a gold cost (it's "zero"). They may only be marshalled by the active player.