Swans ruckman Shane Mumford will be sidelined for three-to-four weeks following a minor operation to remove an infection in his back.

The Swans big man was a late withdrawal from the team’s round two clash with Fremantle, before back pain ruled him out of last weekend’s match against North Melbourne.

This week, Mumford was diagnosed with an infection and was put on a course of antibiotics.

However, Swans General Manager of Football Dean Moore today confirmed the problem area had not responded to the antibiotics.

“The infection in Shane’s back did not respond to treatment as we had hoped, so he underwent a simple procedure to remove it,” Moore said.

“He is recovering well and we expect him to resume training in around seven days, with a view to have him available for selection in the next three-to-four weeks,” he said

In Mumford’s absence, Mark Seaby has been in good form, containing North Melbourne’s Hamish McIntosh and Todd Goldstein last week, and putting in an impressive performance against the Dockers’ big man Aaron Sandilands in round two.

Swans second-ruck option Lewis Roberts-Thomson is also in contention to return to the side this week, following two weeks on the sidelines with a fractured cheekbone.