Adelaide ruckman Reilly O’Brien has revealed midfield teammate Cam Ellis-Yolmen is in doubt to return against Port Adelaide.

Ellis-Yolmen missed the game against Geelong on Friday night due to a shin problem and the niggling injury could rule him out for a second week.

“I don’t think he got through the full session, so he’s probably in doubt for this week,” O’Brien told reporters on Wednesday.

“We’ll see what happens in match committee.”

As for Tom Lynch and Wayne Milera, O’Brien said both trained well.

“They looked good out there, but it’ll be up to match committee and how they pull up from the session – sometimes you can pull up a bit limp, but we’ll have to wait and see,” O’Brien said.

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Ahead of Saturday’s Showdown, the 23-year-old said he would be wary of an in-form Scott Lycett and the potential return of Patty Ryder.

“He’s had a great few weeks and is in awesome form, so it’ll be a huge challenge, but I’m looking forward to it,” O’Brien said.

“He’s a competitor like me so it should be a good battle all day – that’s what we play for.

“I had that match-up [Lycett and Ryder] last Showdown so I sort of know what to expect from those to and I’m ready for whatever challenge they throw at me and the group.”

Now with 14 AFL games under his belt – 12 of those this season – O’Brien said he was looking to increase his ability to push forward and impact the scoreboard.

“Early on I was a bit slow with the ball, but now I’ve adjusted to it and I’m feeling more confident will the ball in hand now,” he said.

“The best ruckman push forward, take marks and kick goals, so I really want to add that to my game.”

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Despite the selection competition, O’Brien said experienced ruckman Sam Jacobs has been consistently supportive over the past few months.

“We’re both competitive guys so we obviously both want the spot, but Sam’s a great guy and he wishes nothing but the best for me and I’m the same for him,” he said.

“We have a great relationship, there’s certainly no awkwardness there.

“He gives me advice each week, he was in the rooms at half-time last week giving me advice.

“He’s come up against the guys I’m coming up against and gives me tips about them.”

The Crows and the Power will compete for the Variety Showdown Shield this Saturday at Adelaide Oval.