Looking at last year's prospect development roster there were no free agent invites. All the players were draft choices, free agent signing and AHL signings.
Goalies: Garand, Lindbolm, Boyko -- Could have the same three this camp
Defense: AHL signees Luke Martin and Louka Henault, both gone and replaced by Zach Berzolla and Will Barton;
Draftees: Jones, Robertson and Skinner
Traded: Emberson
Free Agent: Scanlin
Skinner is gone and Jones seems unlikely. That will leave them two short. Perhaps as has been speculated Khellberg or a Cincinnati contract or a free agent invitee (Ryan McCleary and Joe Amstem were WHL invitees to prospect development camp)
Forwards: Draftees: Sykora, BMB, Pajuniemi, Cuylee, Henriksson, Rempe, Othmann, Korczak, Edstrom, Barbashev, Grubbe
Free Agent Signees: Trivigno, Khodorenko
Pajuniemi, Grubbe and Khodorenko are gone, probably replaced by Berard, Dylan Roobroeck and the two AHL signees, Panwar and Pekar