Blues coach Vern Cotter said Sullivan would give them a little extra length in their kicking game to get them into the corners and trap the home team in that area.
"But he's got other things he brings to his game, and he is fresh. He's been helping the team prepare in the last couple of weeks against the Waratahs and the Chiefs, and he gets an opportunity out there.
While conditions forecast for game time could be wintry, Cotter said kicking would not dominate the game.
"There will be periods when it's a game of chess, and there'll be periods when it opens up and it will be having the timing right when they felt it was the moment to go.
"The Crusaders are a good team, it's going to be a tough game. It starts with the set-piece and making sure you get your own ball."
They showed their approach against the Reds through their scrum, lineout, and field position.
"Both teams will try to get into the right part of the field. The set-piece battle will be there; from there, it'll go to collisions and get over the advantage line. Once you do that, you get options for developing the game.
"It's pretty basic so we need to nail it down and be as accurate as we can."
Cotter has revelled in the Blues' recovery, and while it could be said there was a nothing to lose attitude about the game, they were positive and enjoying the chance they have created.
"We're aware of their record, 30 games without losing. One day they're going to lose and that is the pressure on them. We're going to enjoy the contest. It will be tough, but that's what you expect at this time of year. If you think it's going to be something else, you're kidding yourself."
The pressure of that record could be an issue, something he knows about.
"When I was at Clermont, we won 77 games in a row. At the end the pressure was heavy. We knew it [a loss] was going to happen and it's the same for the Crusaders. They've got 30 and is it this week or not? I don't know but the boys will be pushing as best they can."
But for the Blues, after beating the Chiefs last weekend, they had come right at the right time of the year.
"It's about enjoying it, helping each other and getting up for these ones, which could be for 80 minutes or longer.
"It's about preparing as best we can, trying to do things we plan, but also when things don't go to plan, adapting as best we can so we limit the damage and get that initiative back again."
Cotter said the key for the Crusaders was understanding the game and its most essential parts. They also know how to win big games.
"That's why in the last eight years, only two teams have won this competition."