St Kilda defender Sam Gilbert will miss the next three to four weeks after having surgery on his hand on Saturday morning.

Gilbert suffered a hand injury in the final quarter of the Saints' 61-point loss to Essendon on Friday night, after having his hand stomped on.

Triple M's Dr Rohan White said the bone was piercing through Gilbert hand while he was sitting on the bench.

"We're just having a closer look, he's got a splint on that, (it's) heavily bandaged," White told Triple M's coverage on Friday night.

"It's what we call an open fracture: the bone was actually coming through the skin on the palm of his hand."

Gilbert has played every game in 2017, with round 18, 2015 the last game he missed for the Saints.