ST KILDA draftee Jack Bytel is headed for surgery on his troublesome back, placing his debut season at Moorabbin in doubt.

The 18-year-old will go under the knife on Friday to correct a bulging disc in his lower back that he nursed throughout 2018.

PLAY AFL FANTASY Make your team now

With Bytel having undergone an intensive medical screening in the lead-up to last year's NAB AFL Draft, club doctors felt surgery was a likely option before he was selected at pick 41.

In his early time at the Saints, Bytel has been restricted to running on the weight-bearing AlterG treadmill away from the main group. 

CLUB LISTS COMPARED Oldest? Youngest? Most experienced?

"Jack is a player with a lot of promise, and he couldn't have been more impressive in terms of his character since joining the club," head of football Simon Lethlean said.

"We knew when selecting Jack that his injury would likely require surgery, but we wanted to see him complete a block of rehab training to know for certain that it was the best option.

"The specialists are confident this procedure will allow Jack to put this injury behind him and we look forward to Jack becoming the player we know that he can for the Saints over the coming years."

FULL FIXTURE Every round, every game

Bytel is expected to have a recovery period of four to six weeks before he slowly increases his training program in the first half of the season.