Premier League Squad

So the registered squad (excluding U21 players) for the first half of the season was:

Arter, Harry Nicholas*
Bamba, Souleymane
Bennett, Joseph*
Camarasa, Victor
Connolly, Matthew Thomas Martin*
Cunningham, Gregory Richard*
Damour, Loic
Ecuele Manga, Bruno
Etheridge, Neil Leonard Dula*
Gunnarsson, Aron Einar Malmquist
Hoilett, David Wayne*
Madine, Gary Lee*
Mathurin-Harris, Kadeem Raymond*
Mendez-Laing, Nathaniel*
Morrison, Sean Joseph*
Murphy, Brian*
Murphy, Joshua*
Paterson, Callum Thomas Owen
Peltier, Lee Anthony*
Ralls, Joseph William*
Reid, Bobby*
Richards, Ashley Darel Jazz*
Smithies, Alexander*
Ward, Daniel Carl*
Zohore, Albin

Madine has left on loan, and it looks like Connolly is off too. Tomlin and Pilkington have left the building also.
So who is going to replace these players? Why would they get rid of players without having replacements?
I think it is likely that Healey will be in the 25 man squad when it is resubmitted.

Jazzy Jeff, Zohore, and Ward have been injured for the most part of the season - i'd imagine they will be retained in the squad due to lack of numbers and potential participation. But currently we're not going to be able to submit a full 25 man squad.