THE LAST time Adelaide met this week's opponent St Kilda, Crows ruckman Reilly O'Brien was a spectator as he searched for form in the SANFL after the "necessary experience" of being dropped. 

It was the 27-year-old's second week out of the team after an underwhelming start to the season, creating a rare opportunity for sidekick Kieran Strachan to lead the ruck against duo Rowan Marshall and Paddy Ryder as the Saints powered home to a 21-point win at Adelaide Oval. 

O'Brien, who has played all 20 games since at AFL level, was quick to recall that experience this week when asked about his history against Marshall, with the pair sharing similar career trajectories after being drafted as rookies and debuting a year apart in 2016 and 2017 respectively. 

As the pair get set to go head-to-head on Sunday as their teams' No.1 big men, O'Brien was certain he was in a better position now to service his midfielders than when the axe fell last year. 

"I wasn't playing the way I wanted to at the start of last season, and I needed that as a bit of a reset," O'Brien, whose 85 career games sits just behind Marshall's 94, told AFL.com.au this week. 

"Ongoing, it probably makes you a little bit hungrier and more on your toes knowing that things can turn pretty quickly, so you don't take your form and training standards for granted. 

"It took a little bit to get my confidence back after that, but I certainly got to a state of playing more natural footy and I certainly feel like I'm doing that this year and continuing to build towards some good footy. 

"It was probably a necessary experience in the end."

O'Brien rated Marshall's season so far as "outstanding" and was prepared for a significant challenge competing with the St Kilda big man's work both around the ground and at the coalface. 

While some increased accountability will be required, the 2020 club champion said bringing his own strengths to the game would be important after a start to the season that has seen him rank No.2 in the AFL for hitouts to advantage, behind Fremantle's Sean Darcy.   

"Matching him in and around the contest, which I think is a strength of mine, and then testing him forward [will be a focus]," O'Brien said. 

"But also having a bit more accountability in terms of knowing he's going to impact offensively … because he does tend to have more impact in terms of getting the ball than most ruckman in the League.

"Personally, I feel like I'm having reasonable impact in terms of hitout numbers, and my follow-up around the stoppages has been back to a reasonable level. But there's another level to go to."

Creating a culture of player-driven feedback has been a focus for the Crows this season under new captain Jordan Dawson, and O'Brien's past two weeks have provided an example of how it can be effective. 

In the one-point loss to Collingwood in round seven, O'Brien's impact around the ground waned in the fourth quarter, collecting just one disposal and one mark to go with his 10 hitouts. 

Against Geelong last Saturday, with that fadeout still fresh in his mind, the ruckman produced an excellent final term with seven disposals, three marks and a massive 16 hitouts. 

The Crows didn't get over the line, but it was an experience that the ruckman said was valuable as the players continue to build a culture of providing and acting on feedback.   

"Every week as players we try and drive a lot of the coaching and feedback and values we want to live and play by as a group, rather than the coaches having to do everything," said O'Brien, who is a member of the Crows' five-man leadership group. 

"With 'Daws' as skipper and the other leaders, we want to drive a player-driven culture and set of values on and off the field. 

"It certainly stung the week before, both individually and as a team, not playing our best in that last quarter, and we didn't want to have that feeling again. It lights a fire in you to make sure you elevate your game in similar situations. 

"The next time it's going to be a close game in the last quarter, I think the whole team will have games like that Collingwood game in the memory in terms of avoiding losing like that."