Dorrington has not been on a loan, nor a pre-season as yet.
So I'd guess he goes on a loan next season (maybe Championship) and probably after Christmas this season to a L1 club followed by next preseason. So its more likely 26/27 (season after next) when he's likely to be in contention at Spurs.
Next season, 25/26, Phillips will have completed a full Championship loan so probably experienced enough to play PL but still only aged 20, whilst Vuskovic only aged 18/19 but with experience in several leagues.
One or either could go out on loan again - both still young to be a PL CB - or join Romero, Van de Venn and Dragusin in spurs first team squad. Nice problem to have in many ways.