If he is unable to prove his fitness for the must-win June 18 clash against NSW, Melbourne's Will Chambers looms as the man most likely to replace him after spending all of the camp before Origin I with the Maroons.
Parramatta veteran Willie Tonga, who played the last of his eight Origins in 2011, won his call-up due to concern over Slater, who hasn't played since game one which was won by NSW.
The 30-year-old Eels centre's experience will be a big plus for a match Queensland must win to keep alive their hopes of winning a ninth consecutive Origin series.
Queensland Rugby League chairman Peter Betros explained the injury dramas had necessitated such a large squad being named.
"We normally announce 19 players but tonight because of the uncertainty over several players we're going to announce 22 players," Betros said.
"As the week goes on and the injury situation becomes clearer, Mal (Meninga) will finalise the team and get it down to the required number."
Canberra youngster Milford could also replace Slater and would make his Origin debut if chosen.
Brisbane halfback Ben Hunt may also get the chance to play Origin for the first time after being included as cover for Cherry-Evans, who failed to finish Manly's match against Canterbury on Friday night due to his knee problem.
Broncos forward Sam Thaiday has also been included in the squad after missing game one due to a calf injury.
Warriors enforcer Lillyman will add cover to the Maroons forwards.
Queensland squad: Darius Boyd, Will Chambers, Daly Cherry-Evans, Matt Gillett, Aidan Guerra, Justin Hodges, Ben Hunt, Greg Inglis, Jacob Lillyman, Chris McQueen, Anthony Milford, Nate Myles, Josh Papalii, Corey Parker, Matt Scott, Billy Slater, Cameron Smith, Brent Tate, Ben Te'o, Sam Thaiday, Johnathan Thurston, Willie Tonga.
- AAP
