YOUNG St Kilda forward Ben Long will be out for up to 10 weeks after he suffered a fractured metatarsal in his right foot.
The Saints will have to rejig their forward line ahead of their match against Fremantle, with Paddy McCartin set to miss one to two weeks with whiplash.
McCartin, who has a history of concussion issues, suffered the whiplash in a collision in St Kilda's loss to Melbourne at Etihad Stadium on Sunday afternoon.
He had already clashed heads with Neville Jetta earlier in the match, but did not get concussion from that incident.
WATCH: Paddy's head clash
"Paddy will probably miss a little bit of footy. How much? I'm hoping it will just be a week or two. He hasn't pulled up as well as we would have liked," coach Alan Richardson told Fox Footy.
"It was … not so much that head clash, although that was a reasonable hit, it was pleasing he had his [concussion test] at half-time and it was as good as he has ever been.
"It was actually the one later when he went back with the flight and got pretty significant whiplash. He had a bit going on during the day, Paddy, so we're hoping it will only be a couple of weeks."
Long, 20, reported soreness after the loss to Melbourne and was found to have suffered a fracture in his third metatarsal.
He was nominated for the NAB AFL Rising Star Award in round five and has been one of the few positives for the club this season, with his toughness, skill and speed standing out.
"Ben has been one of our most in-form players over the first seven rounds and has really cemented his place in our best 22," St Kilda football manager Simon Lethlean told saints.com.au.
"He'll do everything right to be back on the field as quickly as possible and we should see him pushing for selection not long after the mid-season bye."
Long has played 11 career games since being drafted at No.25 in the 2016 NAB AFL Draft.
Backmen Sam Gilbert (ankle) and Shane Savage (corked thigh) are expected to be available for the clash against the Dockers on Saturday night at Optus Stadium.
Jack Lonie (31 disposals and two goals) and Jack Sinclair (30 and one goal) could be possible inclusions after impressing for Sandringham in the VFL.