Fremantle's finals campaign has been dealt a mammoth blow with Michael Johnson to miss the rest of the season because of injury.
The defender, a mainstay of the Dockers defence, has a major back complaint that will force him to the sidelines for more than a month.
Johnson consulted a specialist today and was advised to undergo exploratory surgery.
"Michael played out Saturday's game under some discomfort," general manager of football operations Chris Bond told the club website.
"We were hopeful that it could be treated and he would be able to play during our finals' campaign but the medical advice we now have is that there are no other treatment options available and an operation was considered the only appropriate course of action.
"Michael will have the procedure this week."
The injury will rock the Dockers' plans for Saturday's qualifying final against Sydney at ANZ Stadium.
Fremantle are already without fellow key defender Luke McPharlin and are expected to come up against a Swans attack boasting dynamic duo Lance Franklin and Kurt Tippett.
Alex Silvagni, a late withdrawal last round, is certain to come into the Fremantle line-up as coach Ross Lyon tries to plug some holes.