Slaggert turns 22 in June. He doesn't have to go to Rockford, although he's waiver-exempt and certainly could. He's waiver-exempt until 2026-27 so you put him in Rockford as opposed to multiple game press box stints as a 13th/14th forward, or even perhaps a 12th forward playing eight minutes a night. I'd be surprised if he doesn't play some games in Rockford, although he's likely your first injury replacement and thus I can see him spending most of the season in the NHL (if he plays well enough).
I imagine sign 2 UFA Forwards, 0 defensemen, bring back Reichel, Anderson, re-sign Guttman with plans to promote back up. Obviously re-sign Vlasic, sign Phillips and Crevier cheap. Probably re-sign Blackwell. Say goodbye to UFAs T. Johnson, Zaitsev, Tinordi and Megna. Say goodbye to RFAs Entwistle, R. Johnson and Raddysh.
Forwards (14)
Hall
Athanasiou
Foligno
Dickinson
Kurashev
Donato
Bedard
Blackwell
Reichel
Anderson
Guttman
UFA
UFA
Nazar
Slaggert*
Defense (7)
Jones
Murphy
Vlasic
Korchinski
Kaiser
Del Mastro
Phillips
(here is where you can also possibly begin the season with both Phillips and Crevier up, start one of the waiver-exempt guys in Rockford and wait around for an injury or until you just waive whichever of Phillips or Crevier sucks more)
Goalie (2)
Mrazek
Soderblom
Looking at that, probably need a couple for Free Agent forwards for depth as you rarely have everyone healthy at once. Maybe you re-sign Raddysh for cheap as well, and maybe add someone else. Slaggert and/or Nazar can be in AHL as needed if everyone is healthy, and you can find some callups out of Dach/Rolston/Luypen/Hayes/Ludwinski/Savoie/Misiak as needed.