The 21-year-old Brisbane powerhouse can play wing, fullback and centre, and has told Slater he is prepared to turn out as a middle forward if required against NSW in Sydney on Wednesday night.
The Maroons have not traditionally carried an outside back on the bench, but in four of the last six Origin games they've had to replace at least one during the match.
Slater has a plan to inject Cobbo - but is not about to reveal it.
"It's a game of footy. There are risks everywhere, but they are calculated decisions," Slater said when asked if Cobbo's selection was a risk.
"This is what we feel is best for our footy team.
"There doesn't have to be an injury for Selwyn to be on the field. He will be out there. I'm looking forward to him getting his game on.
"We have a plan around injecting Selwyn into the game. We are across that. I'm not going to stand here and tell you all exactly how.
"I would love to tell all our Queenslanders how we are going to play, but that's what makes it exciting."
Slater said Cobbo could "play anywhere".
"He is a big body and a wonderful player, so he may pop up anywhere," Slater said.
Maroons captain Daly Cherry-Evans was an Origin super-sub in his formative years and reckoned Cobbo would do a stellar job whenever he was called on.
"With the super-sub role there are two things that are really important," he said.
"You put the team first and you bring your strengths to the team. If Selwyn does that he is going to be fine.
"Selwyn is a talent. He is just a footy player. Any time he's played for Queensland he's done a fantastic job.
"I am really confident in him. He has got a good energy about him. We love playing with Selwyn Cobbo."
Maroons coach Billy Slater (left) and Reece Walsh (right) share a close bond. (Darren England/AAP PHOTOS)
Slater has forged a strong bond with fullback Reece Walsh and is excited for what the Brisbane No.1 can bring to the table in his first Origin match in Sydney.
"I just have to help Reece be him and be as good as he can," Slater said.
"Reece has a great want to be the best he can be and sometimes that gets lost," Slater said.
"He has a great work ethic, he is really respectful, he loves his footy and loves this (Maroons) colour and his state.
"I'm like five-and-a-half million Queenslanders. I am looking forward to watching Reece Walsh play out there tomorrow night.
"He is 21 years old. We all mature with experience and he is going to grow.
"He is a wonderful player now and will be an even better player next year and in five years' time."
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