GEELONG captain Joel Selwood has all but ruled himself out of the club's NAB Challenge campaign but he remains hopeful of being fit for round one.

Selwood has been on a restricted program since December due to plantar fasciitis in his right foot.

The Cats captain failed to train with his teammates at Simonds Stadium on Monday as the club held its open training session in front of about 3000 people.

The skipper told reporters on Monday he was aiming to play in the opening round against Hawthorn, although he also said he would only take the field when he was 100 per cent ready. 

"I've had the layoff before Christmas and I'll start joining back in with the boys in the not too distant future," Selwood said at Simonds Stadium on Monday.

"I'll work my way through that and get up for round one."

Selwood said participating in the pre-season competition was not part of his thinking and instead his focus will be on getting the right conditioning under his belt.

"I've done very little running so far. That starts ramping up around now and I've still got 62 days until that round one clash," Selwood said.

He admitted his recovery had taken longer than he initially thought it would.

"From the outset it's been a lot slower than what we thought it was going to be," Selwood said.

"It started off being a bruised heel and then it went into plantar fasciitis so I've still got a bit of work to do."

Selwood's younger brother Scott is also racing the clock to be fit for the start of the season after surgery on his ankle in October.

Scott Selwood joined Geelong from West Coast as a restricted free agent last off-season, along with Patrick Dangerfield (Adelaide), Lachie Henderson (Carlton) and Zac Smith (Gold Coast).

The 2012 Eagles best and fairest winner joined in one of the competitive drills with teammates on Monday but still has quite a bit of work to go before he is ready to play.

"His best footy is still ahead of him but what he's got to do is get back into some good form," Joel said of Scott's recovery.

"He's got to feel really confident in the ankle, which he's getting at and he's got to keep working away."

Key forward Mitch Clark did not join in training but Selwood said he was on a prescriptive light day, while Cory Gregson, Jordan Murdoch and Rhys Stanley were also on modified programs.

The Cats announced earlier on Monday that Selwood had agreed to a new contract extension until the end of 2019.

"It was an easy decision. It was a pretty frank discussion over two or three weeks.

"With my manager and (Cats football manager) Steve Hocking we sat down and worked out something nice and quick."