St Kilda's worst injury fears have been realised with Jake Carlisle set to undergo surgery that will rule him out for the majority of the AFL season.
The talented defender will have a procedure to relieve pressure on his lower back caused by a protruding disc.
A six-week recovery period will be followed by several months of rehabilitation, making it unlikely the 27-year-old will play a substantial part in the 2019 season.
"When he's playing well, we know Jake is one of the best defenders in the game, so it's obviously disappointing not to have him available," Saints football boss Simon Lethlean said.
"Given he hasn't been able to train with any intensity since Christmas we were able to prepare for the start of the season knowing he would likely be missing, but unfortunately he will now miss a considerable amount of football."
Looking to bounce back afte just four wins last season, the Saints host Gold Coast in round one on March 24 and could be without their best players in Carlisle and Jack Steven, as well as big-name recruit Dan Hannebery.
Four-time club best and fairest winner Steven's immediate future is clouded after he took indefinite leave to deal with mental health issues.
Persistent hamstring issues have denied Hannebery the solid pre-season he needs to improve on an underwhelming finish to his time at Sydney.
Carlisle's absence is likely to hand 20-year-old key position player Josh Battle the chance to lock down a spot in St Kilda's backline.
"Thankfully with Dylan Roberton back, joined by the likes of Jarryn Geary, Jimmy Webster and Nathan Brown, we have good experience in our backline that will be able to help fill the void," Lethlean said.
