It is "far too early" to know if Brent Reilly will ever play football again after the Adelaide defender underwent emergency surgery for a fractured skull on Monday afternoon.

Reilly was involved in a collision at training where he was struck on the left side of the head by a leading player.

He was rushed to the Royal Adelaide Hospital, where he remains in intensive care.

The impact caused a depressed fracture in Reilly's skull, leaving several breaks that required surgery to stabilise the area.

Club doctor Andrew Potter said on Tuesday morning the surgery was completed without complication, and that although Reilly was now heavily sedated, he had spoken to his family.

His parents flew to Adelaide from Melbourne shortly after the incident.

Dr Potter said it was too soon to speculate on Reilly’s playing career, and the Club’s total focus was on the 31-year-old's immediate health.

"I don't think I can answer [whether he'll play again].

"It's far too early… it's less than 24 hours after the surgery.

"As always with any surgical intervention there are some things that occur that are a normal part of the recovery, and we really have to wait until all of that settles down and see how Brent is progressing over the next week or so or even longer before we answer that question.

"He's breathing by himself, his condition hasn't deteriorated overnight – it's remained stable and he's communicated with his wife and family this morning and last night."

Coach Phil Walsh and several members of Adelaide's leadership group were able to visit their teammate on Monday evening and the entire playing group returned to training at Max Basheer Reserve on Tuesday morning.

Crows Head of Football David Noble said all players and staff had rallied behind Reilly and his family.

“I’m sure if we had let it (happen), all the players would’ve felt like they would’ve wanted to go in,” Noble said.

The Club has already put supportive measures in place for Reilly’s family and all players and staff to access where appropriate.

“I think the support network that we put around Jamie and Brent particularly… I think the Club should be proud of the way that our medical team handled that,” he said.

“We’ll brief the players again this morning and just get a gauge as to where they’re at and make sure that support network continues for as long as it needs to, for the players and especially the family.

Reilly will be monitored in intensive care over the next few days as is standard procedure for such an injury.

Dr Potter said he had never before seen in football the type of skull fracture Reilly sustained.

"It's very unusual in football; fractured skulls are a well known complication of all sorts of things particularly high impact activities

"In sport we don't see it too often, occasionally in the high-speed activities like downhill skiing and motor racing."