"I'm expecting another really tough game," said Sinfield. "They've been the form team all year, as the table shows, and to get the win there last week was amazing. We know what it means and what's at stake but now we have to come here and perform against them again.
"Ultimately the team that plays best on the day will win, but we know we can beat them, we'll have to improve on how we played last time but we know we can do it."
The Rhinos earned a much-needed week off from competition following their dramatic one-point win against Wigan in the opening round of the play-offs and Sinfield is hoping the opportunity to rest and recover will help re-energise the team ahead of Saturday's encounter.
"The rest week has been vitally important for us to rest some bodies that have been battered and bruised since January," he said." It's meant that some of the players who would have been doubtful this weekend have had the chance to recover and are likely to play.
"It gives us an advantage in that respect but I don't know if it will give us an advantage in the game, players seem to find positives from whichever route you take, but for us at this moment in time the rest was vital."
Leeds ended the regular season in fourth place and having lost to Warrington Wolves in the Challenge Cup Final, Sinfield's side are desperate to end the season on a high by walking away from Old Trafford on October 2 as Super League Champions for a fourth successive year.
"It's very important for us to get some silverware," said Sinfield. "In the last couple of years we've managed to do that but this season we've lost in a final and the sides probably underachieved a little.
"We've struggled at times and I think the squad we've got warrants some better performances. We've got a chance now to win and we just need to perform, we've played in some big games this season and not performed so that needs to change. I'm confident that come Saturday you'll see the best of us."
Tickets for the Engage Super League Qualifying Semi-final, Leeds Rhinos v Wigan Warriors at Headingley Carnegie Stadium on Saturday September 25 (5.15) cost from £17 (£10 concessions). Family tickets giving admission to two adults and two children cost £50. Tickets are available from the Ticket Office at Headingley Carnegie Stadium (0844 248 6651) and from the Wigan Warriors Ticket Office at DW Stadium (0871 66 33 552).
Tickets for the Engage Super League Grand Final at Old Trafford on Saturday October 2 cost from just £16 (£8 concessions) and are available from the RFL Ticket Office on 0844 8561113 or by visiting www.rugbyleaguetickets.co.uk