ADELAIDE ruckman Sam Jacobs says his side will have a tough task to overcome the combination of ruck skills and goalkicking ability of Hawks opponents David Hale and Jarryd Roughead on Saturday.

The duo has been in scintillating form in 2012, booting 60 goals between them as well as managing more than 600 hit-outs.

Jacobs leads the competition in hit-outs and hit-outs to advantage, but said his Hawthorn counterparts' form around the ground meant they would play a vital role in deciding Saturday's preliminary final.

"They are so dangerous around the ground, they are two different sort of ruckmen as well," Jacobs said.

"They are able to push forward as well and sometimes they kick a lot of their goals while they're in the ruck.

"So they are going to be dangerous, and Haley has been a great ruckman for a long time, so we'll have a good battle."

Jacobs said Hale was one of the most underrated big men in the competition.

" I played against him a lot in the VFL when I was coming through at Carlton and we had some great battles then and he has got a lot to prove still," he said.

If his All Australian snub is anything to go by, Jacobs, too, is underrated by the wider football community.

The 24-year-old was favoured by many to be selected in the side after a career-best season and his status as the key to Adelaide's formidable midfield.

The two Crows players who made the side, midfield dynamos Patrick Dangerfield and Scott Thompson, both attributed their rise in form in 2012 to Jacobs, but selectors overlooked Jacobs and instead opted for West Coast's Nic Naitanui and Dean Cox.

While the Crows ruckman admitted he was disappointed to miss out, he had more important things on his mind.

"That is nice to hear that from those boys; we are all pretty tight in that midfield group and we do bounce a lot of each other and we have worked really well together this year," Jacobs said of Dangerfield and Thompson's praise.

"Naturally you do get disappointed, especially when you hear a lot of people saying 'You should have been in there'.

"But I guess the best thing for me is I'm playing in a prelim this week. It puts it in perspective and it shows I'm here to win a premiership, I'm not here to be All Australian."

The former Carlton ruckman has missed only one game this season, against Geelong in round 18 due to hamstring tightness, despite many pundits speculating he'd be rested towards the latter stages of the regular season.

While he decided against taking time off when the Crows played Gold Coast and Melbourne, Jacobs said he felt fresher for the week off against the Cats.

"On the weekend is probably the best I have felt for a while; Sydney I didn't feel awesome, but on the weekend I felt great," he said.

"I missed that game against Geelong four weeks before the season finished, so now I'm starting to get a lot of value out of that."

Harry Thring is a reporter for AFL Media. Follow him on Twitter: @AFL_Harry.