ST KILDA'S season may be dealt a brutal blow with the club considering sending important key defender Jake Carlisle in for back surgery. 

Carlisle, 27, has been hampered by a disc issue in his back since before Christmas and has struggled to run at times.

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Saints football manager Simon Lethlean told Melbourne radio station SEN an operation would set Carlisle back considerably. 

"He's going to need to see a specialist. Things aren't improving," Lethlean said. 

"He hasn't been able to train properly for most of January and it's not getting better, so we need to assess whether surgery's going to be an option and if it is, that's going to mean a significant chunk of his season is interrupted." 

The club is desperate to have Carlisle avoid an operation. 

"If you're going under the knife, you're certainly looking at three, four, five months (on the sidelines)," Lethlean said. 

"We're not quite there yet but we certainly haven't found an additional alternative that's making it better right now.

"With a back, the doctors try everything else first before you get surgery. I think we'll find out in the next couple of days what the next path is going to be there." 

Saints coach Alan Richardson is set to enter the round one clash with Gold Coast having limited tall defensive stocks.

Veteran Nathan Brown is suspended while youngster Oscar Clavarino will be out for up to two months, recovering from a right ankle syndesmosis sprain. 

Carlisle is likely to be joined on the sidelines by four-time best and fairest Jack Steven, who has stepped away from the club to deal with mental health issues.

"Jack's going to go away for about 10 days to spend some time in a different environment with someone he trusts and just do some things that he likes, which will hopefully include some fishing and some golf," Lethlean said. 

"He's taking a training program with him and if he wants us to send one of our high performance guys across to do some work with him, we will, but he thinks he'll be able to get that work done with the guys he's staying with. 

"Hopefully he comes back in 10 days wanting to reinsert himself in the program but he might not. He needs to reinsert himself when he's fit and healthy to do so."

Making matters worse for Richardson is the likely absence of recruit Dan Hannebery, who is nursing a hamstring complaint.

The 28-year-old is completing a two-week block of hard running before he can re-join full training. 

"He's in a race for round one. He'd be up against it," Lethlean said.