St Kilda forward Paddy McCartin has suffered yet another setback after injuring his right foot during training. 

McCartin sprained his foot on Monday and will be on restricted duties for a month, meaning he won't return to full training until the new year. 

"Paddy has built a really strong fitness base over the past few months and has shown huge improvement in his running capacity," football manager Jamie Cox said. 

"During the second half of the season, through his break, and the start of pre-season, he was able to complete a significant amount of work. 

"He'll be off legs for a few weeks but given he will be back in full training at the start of January, we wouldn't expect his pre-season to be impacted too much." 

McCartin's injury history has been well documented with the key forward suffering six concussions since 2014, limiting him to just 22 senior games after he was taken with the first pick in the 2014 national draft. 

Following Nick Riewoldt's retirement, a vacant spot in St Kilda's forward line is McCartin's for the taking if he can remain fit throughout 2018.