Pledger backs up import centre Shawn Long and is regarded as one of the best interior defenders in the NBL. Lual-Acuil and Smith-Milner will be called upon to step up in his absence.
Both players have been playing minutes off the bench at either centre or power forward this season and both show promise.
With Melbourne keen to build on their five-game winning streak, coach Dean Vickerman will he expecting both to seize their opportunities.
While Smith-Milner has been with United for several years and shown he can provide a physical presence and be a reliable performer on offence, Lual-Acuil is in his first NBL season after playing overseas and college basketball in the United States.
He has a thin, 213-centimetre build but has shown the ability to block shots and bring some energy to the team. He also has the ability to drive to the basket or shoot three-pointers, which could help Melbourne boost their bench scoring.
But Pledger’s defence and rebounding will be what is missed most so both players know that must be their primary focus.
Melbourne United play Brisbane Bullets at Melbourne United on Sunday at 3pm AEDT.