ADELAIDE has lost key defender Tom Doedee for the rest of the season with an ACL rupture in his right knee.

It is a significant blow to the finals hopes of the Crows, who are coming off an upset loss to Gold Coast that dropped them out of the top eight.

Doedee suffered the injury in the first term of Saturday night's loss to the Suns.

Scans on Sunday in Adelaide confirmed the rupture, and Doedee will need surgery.

Doedee also suffered an ACL rupture in his left knee during round one of the 2019 season, sidelining him for the rest of the year.

"Unfortunately it's not the news we were hoping for and scans have confirmed that Tom has ruptured his ACL," Crows high performance manager Darren Burgess said in a club statement.

"He was clearly in some discomfort after coming from the ground on Saturday night and now we have confirmation of the injury which will sideline him for the rest of the season.

"We all share Tom's disappointment and we are supporting him as best we can as he prepares for surgery and then rehabilitation.

"What we know of Tom is he is of high character and the utmost professional, and having been through this process once before, knows what it takes to get back to playing at the highest level."

Adelaide are counting the cost of the disappointing loss to the Suns, with Crows coach Matthew Nicks suggesting analysis of their performance will find some "quite glaring" holes.

Not only did they lose Doedee, they threw away a 35-point lead to the Suns' nine straight goals to lose by 25 points in Darwin.

Adelaide sit ninth on the ladder and still have a 6-6 record, although their 1-4 record away from home is clearly setting off alarm bells throughout the club.

"We need to do better, we know that," Nicks said.

"It's something that is front of mind for us.

"We'll go back and have another look at it but we understand we've just got to be better."