St Kilda ruckman Rowan Marshall will miss at least a month of football after a decision was made to go under the knife to resolve his ongoing plantar fascial issue.

Marshall has had issues with his foot throughout the season and was unable to play out the game against Geelong on Friday night.

Fox Sports' Tom Morris reports Marshall will face four to five weeks on the sidelines as he recovers from surgery.

St Kilda COO Simon Leathlean said the club will give Marshall the time he needs to fully recover from the injury.

“This is a really frustrating injury to manage,” COO Simon Lethlean told the club's website.

“It can seem a bit like one step forward, two steps back, but that is the nature of this issue.

“The only thing we can do is support Rowan and give him the time he needs to recover.”

Marshall has played five games in 2021 after an injury-plagued pre-season forced him to miss the start of the season.

The Saints have confirmed Brad Crouch will also undergo surgery on a fractured cheekbone but is expected to be available for selection against the Bulldogs on Saturday night.