St Kilda have ruled out key defender Jake Carlisle for Saturday's AFL clash with Port Adelaide, while Josh Bruce's season is over after he broke his leg at training.
Carlisle suffered a punctured lung while receiving treatment for a rib injury prior to Thursday's main training session.
Bruce, who had been set to return from a back injury, then collided with a teammate in a marking contest and suffered a fractured fibula.
The Saints have described Carlisle's injury as minor and are hopeful he will only miss one game.
"There is a small risk in treating rib injuries that this type of complication can occur," St Kilda football boss Simon Lethlean said.
"We'd love to have them both out there this weekend but the reality is they won't be, and we will need guys to step up and fill the void.
"We have seen a host of young players take their opportunity over the course of the season, and we need this to continue this week."
The Saints' latest injury setback comes just days after young forward Josh Battle fractured his eye socket during his side's upset win over Melbourne.
Fifth-placed Port Adelaide will start strong favourites against the 15th-placed Saints when the two sides meet at Adelaide Oval.
