Day was injured late in the first quarter of the SUNS' 24-point JLT Community Series win over the Lions, when his right foot stuck in the turf as he contested a ball with Lions defender Jack Frost.

Ashcroft told SEN radio on Monday morning Day had suffered some bone damage in the incident, with his injury more common among car crash victims than footballers.

"It's a once-in-a-lifetime injury I think in footy circles anyway. We haven't heard of it before, but Sam does have a fractured hip dislocation," Ashcroft said.

"His hip did dislocate, it took a bit of bone with it, so it is fairly significant. He gets surgery later today (Monday) and more than likely will miss the majority of the year.

"Even our medical team can't remember a time when someone's done something as significant as this. It's more like a car accident injury.

"Unfortunately for Sam who's had such a great pre-season, he's going to miss most of the year."

Ashcroft said the Suns would have a better idea of Day's likely return date after Monday's operation.