Injured Lewis Johnston a chance to play next week if North Adelaide advance

North Adelaide could regain Lewis Johnston for next week's preliminary final if it can keep its season alive against the Eagles today.

JOHNSTON was ruled out of this afternoon's knockout first semi-final after his ankle pulled up sore from a half-hour training session on Friday.

The Adelaide-listed player was given a painkilling injection during the Roosters' 62- point win over Central District in the elimination final and showed up minor signs of damage in a scan this week.

Crows' football operations manager Phil Harper said his club's doctors examined Johnston and were unable to give him the all-clear.

"He pulled up a bit sore and that was from a half-hour training session - not a two-hour full-on contest," Harper said yesterday.

"He was probably only a couple of days away though, so if North gets through, he could be a chance to play next week."

Johnston's absence is a huge advantage for the Eagles, who have been hit hard by injuries of their own this season.

North's record with Johnston this season is 8-3 - two of the defeats by less than a goal - but only 4-6 without him.

"He's a very good player," Eagles' coach Michael Godden said. "He wasn't in their side when they had that bad patch but I don't think that was just because he didn't play and they were certainly back to their best last week."

Godden dropped his own bombshell yesterday by dropping established defender Byron Sumner to the reserves.

Sumner has been a regular in the senior line-up for the past two years and was the Eagles' best player when these sides met in the elimination final last year.

But coach Michael Godden said the former Sydney Swan player's form had dipped in recent weeks.

"It was a massive call and one we didn't take lightly," Godden said.

"He just hasn't been playing the footy we've been used to recently."

There are three changes to the Eagles' side that lost to West in last Sunday's qualifying final.

Sumner joins Campbell Heath (pulled out by the Power) and Jarred Allmond (knee) on the sidelines.

The replacements are Jake von Bertouch, Sam Martyn and Lachlan Carey - who have all spent the majority of the season in the reserves.