Hunt was considered the front runner to be endorsed as the Maroons' next halfback earlier this month, after his dominant start to the season.
Slater has been touted as a possible Origin replacement after Cameron Smith retired from rep duties on Tuesday.
Smith dropped the bombshell news at a Melbourne press conference today, just three weeks out from the State of Origin series.
Ball-playing forward Harris is a leading candidate for the No. 6 jersey, having famously started a Test there four years ago against Australia.
The mercurial 20-year-old is widely seen as a future superstar and before he took on the Blues job, Fittler last year called for him to be blooded.
Napa is in hot water for dangerous contact charges, with him also putting a blatant late shot on Bunty Afoa.