Whistle left the Steelers in the summer to sign for Tim Wallace’s side and both sides meet in a Challenge Cup double header, starting on Saturday in Sheffield.
And Whistle recalled the reception he got from his once adoring fans when he went back there for the first time with his new club last month.
“It perhaps means more now because Sheffield are my former team, but it’s always a reason to get excited. The rivalry between them is pretty good so it’s a little extra for me,” he said.
“I learned how big these games are last year when I was with Sheffield, but now I’m on the flip side and the atmosphere in both arenas is always incredible,” he said.
“I’ve already been back in Sheffield and I think the reception I got was pretty mixed. It was hard to tell. Some were chanting my name, but I couldn’t tell if it was a positive thing or not.
“I enjoyed my time there, but the ways things happened over the summer, it was kind of out of my control, but I loved the passion of the Sheffield fans.
“The fans in Nottingham are, for me, just as passionate and I like getting the chance to play at home is nice.”
Whistle stalled over staying in Sheffield after being told by head coach Aaron Fox is role would be reduced this season.
But the manner of the departure left a bitter taste in the mouths of Steelers fans, especially on the back of the fact he joined their rivals.
And he’s relishing his role alongside Kevin Carr, with both players sharing netminding duties, but he insists there’s no axe to grind with his former team.
He added: “How I left, I know, still upsets some people, but that’s part of the game and they’ll go against you because you’re playing for another team. It’s kind of the way it is.
“I’ve nothing bad to say about the Steelers fans. What happened with my brother and I wasn’t great, but that’s the way it is.
“I like the role I have right now and it’s not so much a back up role I have. Between Kevin Carr and I, it’s more like ‘1a’ and ‘1b’ and we’ve been splitting every weekend apart from last week.
“It allows us to push each other in training and I believe will make us a lot better over time and help our game go to the next level.
“I’ve no problem with going back there and with a chance to play, you automatically put that little bit of extra effort in and want to beat them.”