"He will have to work through a bit of pain at various times but we are happy with where he is at."
There was no sentiment in selecting Clarke, who hurt his knee in the semifinal victory against the Crusaders and is one of the survivors from the Chiefs' previous final against the Bulls in 2009.
"It is all about trying to win a championship in the weekend. He is an important part of our mob from a leadership and set piece point of view and we are happy to get him out there, but he needed to get to a certain level of fitness and he has done that."
Clarke did some running, change-of-direction agility work and tackling at training to satisfy himself, the medics and the coaches that he was in shape to lead the Chiefs' title attack.
The Chiefs staff had done a great deal of work analysing the Sharks' styles of play, their key players and general patterns, said Rennie.
They were a potent side across most departments and had a strong scrum and lineout.
"They have a lot of good athletes and are very physical so we will need to be at our best up front and they have game breakers all over the park. They can play high-paced footy or kick the ball and look for territory. We have done a fair bit of work in and around them so we have to make sure we front in key areas and give ourselves a chance of winning it."
Rennie added: "It is fantastic to still be in the race for the title, and to be at home so we know we will have a big crowd behind us and we're confident the boys will front."
CHIEFS V SHARKS
Waikato Stadium 7.35pm tomorrow
Chiefs
15: Robbie Robinson
14: Tim Nanai-Williams
13: Andrew Horrell
12: Sonny Bill Williams
11: Asaeli Tikoirotuma
10: Aaron Cruden
9: Tawera Kerr-Barlow
8: Kane Thompson
7: Tanerau Latimer
6: Liam Messam
5: Brodie Retallick
4: Craig Clarke (c)
3: Ben Tameifuna
2: Mahonri Schwalger
1: Sona Taumalolo
Reserves: Hika Elliot, Ben Afeaki, Michael Fitzgerald, Sam Cane, Brendon Leonard, Jackson Willison, Lelia Masaga.