Australian international Sheehan insists he and his provincial colleagues are determined to ensure the Lions don't have an easy ride on the West Coast following their convincing win over the Barbarians and he is predicting a hugely physical affair at Patersons Stadium.
"Bloody hard!" was Sheehan's response when asked what type of encounter he wanted The Lions to experience in their first fixture on Aussie soil.
"It's a game of rugby - we don't want to hold anything back. We want to go at them and let them know what it's going to be like.
"We want it to be an extremely physical game and we want them to know that they've been in a battle.
"It will be just like a Test match for both teams. That's what they want out of it and we're prepared to give to them.
"In terms of Saturday's game, I don't think the Barbarians team was together long enough to form a good attack against them. But we've been playing all year and we know our strengths, so we'll work to those strengths and hopefully we can go at them."
Much has been made of the honour attached to representing Britain and Ireland's elite but Sheehan insists that pride isn't just felt by those fortunate enough to pull on the famous red jersey.
The former Reds and Waratahs veteran, who has seven Qantas Wallabies caps to his name and featured in the Rugby Championship and on the end-of-year tour to Europe, has struggled with injury this season and he insists that facing the Lions is a huge reward for all his hard work in fighting back.
"It's definitely up there as a game you really want to play," added Sheehan, who was out for six months as a result of an ankle injury he picked up just half an hour into his first international start against Italy in November.
"Playing for your country is the greatest honour but being able to play this match with 22 of your good mates is awesome as well.
"It's exciting to be around the young guys who are going to experience playing against The Lions. To be a part of that, to be a senior player in the team looking to help out and get a victory would be great.
"I won't lie - it's been a frustrating year. It's been up and down and it's been a hard road back from a pretty major injury.
"To be able to get the opportunity to start this game is awesome. It's a bit of a reward for all the hard work that's finally paid off. I'm starting to feel good, I'm starting to get the timing back and this is a great opportunity."
It's an opportunity that will live long in the memory whatever the result but one that would be even sweeter if the Force could come out on top.
And while Sheehan doesn't believe victory for the hosts would derail The Lions' hopes of series success, it's obvious that he feels quietly confident that a shock result could be a possibility, even if his side have been forced to draft in some new blood due to the fact that they face the Waratahs in the Super XV on Sunday.
"It would be great for us if we could get the win. It would knock them around a bit, but they're a professional outfit, they're the best players in their teams and countries, so I think they'd bounce back.
"Test matches are different to midweek games - when we've been beaten on tour in midweek matches with the Wallabies, we've always bounced back in Test matches. I don't think it would be that big a deal for them, but of course they'd like to win every game.
"We've got a couple of guys who have come in but they've been here earlier in the year. They know our plays and our moves so it's just about getting the timing.
"Last week we had exceptional training sessions all week. We had a good Wednesday, Thursday and Friday session - there are few little kinks to knock out but it's coming good."