Wheeler needs to be protected. His $8.5M deal starts next year (2019-20 season) and carries a full NMC through the end of the 2021-22 season.
Jets Protected Forwards (7)
Wheeler (NMC)
Scheifele
Laine
Ehlers
Connor
Roslovic
Lowry
Jets Protected Defensemen (3)
Trouba
Morrissey
Someone else - let's say Niku
Jets Protected Goalies (1)
Hellebuyck
Exempt: Vesalainen (and anyone else drafted in 2017 or later - except McKenzie I believe because he's playing pro this year?)
Exposed Forwards: Little (2024), Perreault (UFA 2021), Tanev, Copp, Petan, Lemieux , Dano, Suess, Harkins, Spacek, Appleton, McKenzie, Shaw, Griffith, Kerdiles, Lipon.
Exposed Defensemen: Byfuglien (UFA 2021), Myers, Kulikov, Chiarot, Morrow, Stanley, Poolman, Green, Nogier, Schilling.
Exposed Goalies: Berdin, Brossoit, Comrie
Most of those exposed players aren't currently under contract for 2021-22, but I assume some of them will be (the guys currently on ELCs for the most part: Suess, Harkins, Spacek, McKenzie, Stanley, Niku, Green, Nogier, and Berdin).
Edit: CapFriendly has a Seattle Expansion Draft page
Seattle Expansion Draft Simulator - CapFriendly - NHL Salary Caps