Speaking at the pre-Origin press conference in Melbourne on Tuesday, Slater was asked about Klein and the Queensland coach said he felt it was "unfair" the referee's personal life had been made public.
"To be honest, I personally think it's unfair to have something personal like that be aired publicly," Slater said.
"I feel for Ashley … it hasn't been discussed within our camp and that's my personal position with it. I think it's quite unfair on him."
Klein confirmed he battled an addiction after a report suggested he lost $400,000, with the game's top whistleblower issuing a statement saying his gambling was only on horses and greyhounds and never on rugby league.
"I received help to deal with the problem and closed all associated betting accounts. This was a difficult period of my life but one which did not in any way influence my job as a match official," Klein said.
He was cleared of any wrongdoing by the NRL.
Blues mentor Daley said he agreed with Slater's view it wouldn't impact Klein's ability to do his job at the MCG on Wednesday night.
"It's challenging when things like that get brought up and I hope Ashley has got the right support and people around him, to help navigate the period," Daley said.
"We've got no issues with Ashley being part of the game."
15°C