The Maroons can wrap up the series at Optus Stadium next Sunday after their shock opening game victory but will be without workhorse Cotter, who has been ruled out with a hamstring injury.
Cotter will be sidelined for up to five weeks, putting him in danger of also missing Origin III at Suncorp Stadium on July 13.
Slater was saved further headaches on Sunday when Roosters forward Lindsay Collins, who was also instrumental in the Origin I win, was offered a fine with an early guilty plea for his dangerous tackle on Parramatta's Waqa Blake.
North Queensland forward Cotter showed what will be missed in a barnstorming debut in Sydney, racking up 51 tackles and making 13 runs in an 80-minute performance.
But Carrigan's figures were equally as impressive, clocking 18 runs and 27 tackles from his 65 minute effort off the bench.
Carrigan is likely to be handed the No.13 starting jersey, or Slater may opt for South Sydney forward Jai Arrow and leave the Brisbane gun as a super sub.
Carrigan was shattered to hear of Cotter's injury, with the pair long-time friends, and said he would do what he could to cover his absence.
"It's a massive blow," the 24-year-old told AAP.
"He's the best fella 'Reubs' and he really put the team first last time and played 80 minutes and had a monster of a game.
"It's a big loss and it's definitely going to hurt but Bill has driven the next man up mentality so whoever pulls on that Queensland jersey I'm sure they can do the job."
Carrigan, who also made his debut in Sydney, has averaged 60 minutes a game this NRL season so would have to dig deep to match Cotter's contribution.
"Hopefully I can - I don't know if I can get out 80, that 65 was pretty hard last game but whatever happens happens," he said.
"I'm just trying to back up my form week in and week out and I don't want to be a one-game wonder.
"If I'm lucky enough to get picked again hopefully I'll do people proud."
Arrow was dumped from the third Origin game last year for breaching the NRL's COVID-19 biosecurity protocols when he brought a woman back to the Maroons' team hotel.
He was then named 19th man for the series opener this year, which Queensland won 16-10.
Slater will make one other change to his winning line-up when he names his team on Monday with a replacement required for winger for Xavier Coates, who has undergone surgery after injuring his ankle in the Sydney match.
Cowboys youngster Murray Taulagi is favoured to edge teammate Hamiso Tabuai-Fidow and make his Origin debut although Slater is a fan of Brisbane veteran Corey Oates, who put his hand up with two tries in their Friday night loss to Melbourne.
"Corey has put himself in the frame all season with his form," Brisbane coach Kevin Walters said post-match.
"If they did pick him, Queensland couldn't go wrong. He has been great for us and it would be nice to see him get that reward."
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