JOHN BUTCHER will play in Port Adelaide's side against Geelong tomorrow.

He replaces Matthew Lobbe in the selected side, after the ruckman reported an ankle injury after undertaking agility training last night.

"Last night Matty Lobbe was doing some agility work which he normally does every Thursday night," said Port Adelaide's midfield coach Shaun Rehn.

"He's just given his ankle a little tweak, and being 36 hours before the game he won't come up (in time).

"We expect him to be right next week but it gives John Butcher his first crack."

Although Butcher has battled form in the SANFL since returning from hip surgery at the end of last year, Rehn is confident his hard work in both skills and fitness training this year can reap a reward for the Power on Saturday.

He will provide a significant tall presence against the Cats.

"It's out with a tall, and in with a tall," Rehn explained.

"(His) form in regards to ball in hand hasn't been great for 'Butch', but the effort's been there," said Rehn.

"We've been looking for a way to get Butch into the side.

"He's been training and he's been playing without any restriction now for many weeks. I think we should also remember Butch's form before he came in at the end of 2011 was also not great at SANFL but came in and had a real impact at AFL level."

"There is some risk, but with risk is also great reward - hopefully for Butch we'll get the reward."