MELBOURNE midfielder Angus Brayshaw has suffered his second concussion at VFL level in the space of three weeks during Casey's 31-point win over Sandringham on Saturday.
The 20-year-old was involved in a head knock at the centre bounce at around the six-minute mark of the first quarter and took no further part in the match.
Brayshaw was concussed just a fortnight ago against Essendon's VFL side, when an errant kick from a teammate accidentally hit him in the head, forcing him out of last Sunday's encounter against the Northern Blues.
Casey coach Justin Plapp confirmed to AFL.com.au on Sunday that Brayshaw was concussed in the early stages of his comeback game.
"I think it's mild but he'll be monitored through the week and be assessed," Plapp said of Brayshaw's latest knock.
"A lot of it was based around that he had a head knock two weeks ago, which is unfortunate for the kid because he wants to get back out there playing footy."
Plapp described the collision as "not a big incident", but the Casey coach added the Demons' ball-winner was not able to return to the field after failing a concussion test.
"He'd gone through the process and they [the medical staff] weren't satisfied with what had come back," Plapp said.
"To what extent, we still don't really know but it was pretty precautionary around that type of injury."
It remains unclear whether Brayshaw collided into a teammate or an opposition player at the contested ground ball.
Brayshaw has played 24 games for the Demons since being recruited with pick No.3 in the 2014 NAB AFL Draft, including three appearances this season.
His start to the year was interrupted by a knee injury he suffered against Port Adelaide in the NAB Challenge in late February.