I'm trying to figure out what type of player the Red Wings want him to be, and also the type of player he wants to be.
When you have a Franzen - Datsyuk - Bertuzzi line you have a sniper - playmaker - grinder on the same line. When you have a Zetterberg - Filppula - Hudler/Cleary line and you say that Filppula is the playmaker then you are asking Zetterberg or Hudler/Cleary to be the sniper or grinder. Not sure that Hudler is an effective grinder (although Cleary can be at times) and Zetterberg has not proved to be an effective grinder; as others have stated, he either gets stopped immediately when entering the offensive zone or keeps the puck and circles around behind the net and turns the puck over when attempting to pass through the slot/high slot. Or if you are asking Zetterberg to be a sniper then he has not shown the skating ability to get open/cut quickly to the middle to get a decent shot.
He is still super strong on the puck, and he doesn't get stopped immeditately. It's just that he seems to be a half step slower, and his shot is a little watered down.