ADELAIDE has suffered a major blow ahead of its clash with Essendon with spearhead Taylor Walker ruled out through injury.

Walker had been progressing in his recovery from a neck strain suffered against Brisbane last Friday but has also been dealing with a chest muscle strain and won't fly to Melbourne for Friday night's clash at Marvel Stadium.

"He was tracking really well at the start of the week and he was quite confident he would get himself up to play," coach Matthew Nicks said on Thursday.

"In a weights session (on Thursday) ... he just found he wasn't moving as well as he'd like.

"There's still a little bit of soreness there that he's not going to be anywhere near ready to play. The fact that he didn't get out on the track this morning (indicates that)."

The 31-year-old Walker sits second in the Coleman Medal race with 41 goals in 14 games and leaves a substantial hole in Adelaide's forward line.

"He's disappointed - he wants to play every game he possibly can and get amongst the younger group," Nicks said.

"But it looks like we come into a nine-day break next week, I think it'd be silly for us to try and push too hard with him at the moment and in the end it was his decision this morning."

Nicks said if the injury tracked as expected, Walker should be able to face West Coast in the following round but the Crows would continue to be cautious.

Defender Luke Brown has also been ruled out amid ongoing Achilles soreness.

Brown will have scans and consult a specialist and Nicks said he and the defender believed it was "more than likely" he would have surgery to set him up for 2022.

Essendon will be without skipper Dyson Heppell, who had thumb surgery on Wednesday.