Rules for the Expansion draft are as follows: each team can only protect 7 forwards, 3 defensemen, and 1 goalie. Or they can protect 8 skaters and 1 goalie. In addition, anyone with a no movement clause must be protected and counts against the protected number. A full list of the rules can be found on nhl.com.
As of now, the Wild have four players with no movement clauses: Mikko Koivu, Jason Pominville, Zach Parise, and Ryan Suter. Assuming that does not change, the team is left with four forwards and two defensemen they can protect on the roster.