Harrison’s men host last year’s Grand Final winners in front of the Premier Sports cameras, seven days after drawing 18-18 with Batley Bulldogs in their last pre-season friendly.
Harrison said: “It’s a big challenge. It’s the first game of the season and both teams will be ready and up for it.
“We’ve been weather affected and we’re maybe a bit behind where we’d like to be, but we’re looking forward to getting going now. We’ve trained ever so well this week.”
On Sheffield, Harrison said: “They’ve had a stable squad for the last few years, built on a big forward pack and few Islanders who can make things happen.
“They’re a very dangerous team, both in the middle and on the fringe, and we’ll be tested defensively right across our line.”
Sheffield coach Mark Aston said: “We planted the flag last year and now it’s time to back it up. It’s going to be tough, because there are a lot of quality teams and there are more games. There’ll be a lot of teams trying to knock you off.
“We enjoyed winning the Grand Final and pre-season has been great, but it’s back to business now.”