Nick Riewoldt has been ruled out of this weekend's clash with Melbourne.
The St Kilda star suffered a concussion last weekend against West Coast, with St Kilda making the decision not to name him late on Thursday.
St Kilda general manager of football performance Jamie Cox confirmed Riewoldt wasn't quite right to line up.
“Nick copped the knock late against West Coast and hasn’t quite got back to 100 per cent,” he told saints.com.au.
“As he hasn’t passed the subsequent concussion tests he won’t face Melbourne this weekend."
Cox said Riewoldt will have to pass more tests next week, but should miss just one match.
“We’re hopeful Nick will only miss one game but he will go through the standard concussion protocols next week before being declared available for selection.”