The Robins got their Super League season off to a flying start with last week’s memorable last-minute 18-16 win over Hull FC.
However, they head to a Warrington side who are one of the competition favourites, a billing enhanced after they swept aside Leeds Rhinos in their opener.
Asked what the Hull success did for spirits, Sheens insisted: “I’m trying to throw the derby off.
“I think the guys have got to understand that we won it in the last few seconds – it could have gone either way though we led with 10 minutes to go.
“We’re not going to rely on the last six seconds every week to win a game. We’ve got to be realistic – it was a good win, but the players have got to throw it away now.
“Warrington at their place is going to be a different beast.
“They’re a very good side even with a couple out through suspension; their depth is huge.”
Although forwards Ben Westwood and Toby King start bans, Warrington can call upon former Tonga prop Sitaleki Akauola and England Knights back-row Harvey Livett to come into their 19-man squad.
Tonga star Ben Murdoch-Masila, a £175,000 buy from Salford Red Devils ahead of last season, did not even make the 17 last week so he should come into the side, too. Warrington proved far too strong and fast for a big-spending Rhinos side that has been heavily tipped as well.
Sheens added: “Leeds have got a fair bit to do and that’s our issue, too.
“(Josh) Drinkwater and (Kane) Linnett have only been in the country four weeks at the time of the derby.
“Kane had only played half a game, as had Josh and Danny McGuire together.
“There’s a long way to go yet in the combinations, but I’m offering no excuses. We can be better. We need to be if we’re going to run with sides like Warrington, particularly away.
“Stefan Ratchford at full-back is one of the best in the game at the moment.
“Their spine is deadly, and that’s something we have looked at and will have to work hard against defensively.
“We did last week, but Hull got us on the edges a few times. We need to fix that.”