ADELAIDE defender Nathan Bock has been ruled out the club’s clash with Essendon at AAMI Stadium on Saturday night after failing to train on Thursday morning.

Bock was confident of overcoming a groin strain he sustained at training two weeks ago, but will be sidelined for at least another week.

Midfielder David Mackay, who sprained his ankle in the win over Melbourne, also watched the Crows' final training session of the week from the sidelines.

Mackay is still in a moon boot and coach Neil Craig said he expected the 21-year-old to miss the next three to four weeks.

“Mackay’s injury is not dissimilar to that of Bernie Vince. It’s a reasonably bad ankle and it’s probably going to be sore for the rest of the year, but you saw Bernie play last week,” Craig said on Thursday.

“Bernie’s ankle isn’t perfect, but he was able to perform pretty well. I’d say he (Mackay) will be three to four weeks, which is really disappointing because he’s an important player for us.

“Nathan Bock was not ready to play this week, but I’d like to think he’ll be ready to play next week. I guess the decision then will be whether we bring him straight back into the team or [play him] in the SANFL. He’s missed a lot of training and hasn’t been able to do a lot of work with that particular injury.”

Mackay’s injury opens the door for one of Jason Porplyzia, Jared Petrenko, Jack Gunston or rookie Chris Schmidt to return to the side.

Craig also confirmed Adelaide would take both Ivan Maric and Jon Griffin into Saturday night’s game despite news Essendon big man David Hille was set to miss after re-injuring his hamstring at training.

The Crows have won eight of the last 11 games played between the two sides, but are yet to claim consecutive victories this season.

Adelaide emerged from the mid-season break with a more committed performance against the Dees and Craig said the onus would be on the team to repeat the effort this weekend.

“Our general form in games has been two good quarters and then one bad quarter. On the weekend you could argue that we had a reasonably even contribution. Melbourne had a bit of control in the third quarter, but not to the extent where you get blown out of the water for a quarter of footy,” Craig said.

“If we can play with that level of consistency in terms of our competitive nature and stay in touch with the game then we’ll be good enough to put some wins together. If not, then we’ll continue to see these [up and down] results.”

Craig said the players were committed to rebuilding their good reputation across the AFL in the remaining nine rounds, but that the mid-season break had failed to pinpoint an exact reason for the decline in attitude and performance.

“Some of it was bad luck [with injuries], but we would be naive to say, ‘It’s all just bad luck and we’ll be better next year’,” Craig said.

“There’s nothing I can do about Andy Otten swerving for that ball at training and doing his knee ... but there’s some other stuff we need to tidy up on and be more diligent with.

“We’ve started that process and we’ll continue that process throughout the year and the end of the year to try and address any issue we have control over to make it better ... we owe that to ourselves and our supporters, big time.”