GEELONG premiership defender David Wojcinski will be watching from the sidelines as his teammates start their premiership defence against Port Adelaide on March 20.

The dashing backman is out for up to a month after undergoing surgery on a tendon on his little finger.

Wojcinski suffered the injury in Friday's practice match against Richmond.

"He's a player we'd like to pick but that's what happens in footy, you rarely have your best 22 available," Cats football manager Neil Balme said.

"We will miss him but we have to cope with that."

The Cats will now have to make a minimum of three changes to their premiership side for round one of the home-and-away season.

Wojcinski, Nathan Ablett (indefinite retirement) and Steven King (traded to St Kilda) won't be running out for Geelong against the Power at AAMI Stadium.

And injured defender Matthew Egan may not be back any time soon either.

Balme said Egan is yet to start to run after a second operation on his injured foot.

Egan had three screws inserted into his foot last September but required further surgery this year to have one of the screws removed.

"With Egan, we're obviously disappointed in some ways it's not going as quick as we'd like it to be," Balme said.

"But we'll take all the time that's necessary to make sure he's 100 per cent because those navicular things are pretty sensitive.

"He's a very well balance organised young bloke. It would frustrate most, obviously he's a bit frustrated but he's a pretty thoughtful guy and he's coping with it well."