The wife of allegedly murdered Adelaide Crows coach Phil Walsh has been discharged from Flinders Medical Centre after being treated for stab wounds.

Meredith Walsh left the hospital after spending the night there with a wound to the leg.

Her son Cy was originally taken to the same medical centre before being remanded in custody after a beside court hearing yesterday.

Cy Walsh. (Supplied)

The 26-year-old is believed to still be heavily sedated and was unable to give his lawyers any instruction before the hearing.

His lawyer made no application for bail and Cy Walsh will face court on September 15.

Mrs Walsh's daughter Quinn is expected to arrive back in Australia from a trip to America this afternoon.

The AFL career of Phil Walsh View Gallery

Meanwhile, police are reportedly investigating the possibility Cy Walsh could have been using ice when he allegedly stabbed his father to death in their Adelaide home, the Advertiser has reported.

Investigators also believe a South Australian taxi driver may hold the key to unravelling what exactly happened in the lead up to the alleged stabbing murder of Adelaide Crows coach Phil Walsh.

They are appealing for the cabbie to come forward and allege he may have seen a man walking at the intersection of Brighton and Jetty Road “covered in blood” at around 2am, shortly after Walsh was allegedly stabbed to death inside his own home.

Police said they had been unable to identify to the taxi driver but believe it was a man.

Cy Walsh, 26, has been charged with his father Phil's murder. (Supplied)

Phil Walsh was found dead with multiple stab wounds in his beachfront Adelaide home at about 2am.

The AFL community is still in shock, following the shock discovery early yesterday morning, even deciding to cancel this weekend’s Adelaide v Geelong clash.

Speaking at a press conference with club CEO Andrew Fagan, Mr Chapman said he first became aware of the alleged murder this morning when South Australian police contacted him about 3.30am.

Phil Walsh. (9NEWS)

Police have removed a knife from the boot of a car at the Walsh residence, but it is unknown if it was used in the alleged murder. (9NEWS)

“A phone call from police to say a tragedy had unfolded and that it involved our coach Phil Walsh,” he said.

“That’s a phone call no one ever wants to get.”

The club then immediately went into “crisis mode”, notifying senior staff.

“There’s no rule book for this,” Mr Chapman said.

“It’s not a one size fits all answer, everyone is going to cope in their own individual way.

"This is a crisis unprecedented."

Mr Chapman stressed that the focus was now on providing support for Walsh’s family and wife Meredith as well as players and team staff.

“It’s about offering all the support we can provide and we’ll keep doing this for as long as we need to…. This, it’s just devastating.

“Today is all about wrapping our arms around the Adelaide Football Club’s community.”

The Crows’ CEO Andrew Fagan said the decision to not play this weekend was in the best interest of the players.

“They’ll want to get out and play, they’ll want to play at some stage,” he said.

His coaching style was distinctive and intense, sparking fears of burnout and motivating the club officials to urge him to find a better work-life balance.

“But this weekend was just too soon.”

The pair described Walsh as “an inspiring leader” who cared about his troops and “was good at his craft”.

AFL CEO Gill McLachlan earlier announced that Sunday's game would not go ahead after the shock death.

Adelaide Crows coach Phil Walsh.

"There have been discussions about the game on Sunday, and even the round. We have decided that the game on Sunday between Adelaide and Geelong will not go ahead," he said at a press conference this afternoon.

The AFL made the decision to call the game off as a "mark of respect to Phil Walsh".

Mr McLachlan said it was unfair to ask the players of both teams to play so soon after Walsh's death.

"While playing footy can be part of the grieving process, we're strongly of the view that it's not fair to ask the young men of the Adelaide Crows or the Geelong Cats to play under these circumstances," he said.

He also said the premiership points will be split between the two clubs as per the AFL rules.

Police have asked anybody who may have seen Cy Walsh on Brighton Road between 1.45-2.30am today to contact CrimeStoppers urgently on 1800 333 000.

He is described as being 180-185cm tall, of thin build with spiky blonde hair.

He was wearing a dark top and dark pants with grey and brown Converse shoes.

Police have claimed Cy Walsh, who lived with his parents, had been out before returning near 2am.

It is alleged a family argument escalated before he stabbed his father multiple times.

Police said he then fled the scene and was found at an address in Glenelg East after a search.

AFL Players' Association CEO Paul Marsh promised its full support for affected players.

"On behalf of all members, the AFL Players' Association offers its deepest sympathies to the family, friends and colleagues of Adelaide coach, Phil Walsh," the statement read.

"Our focus from here is the well being of the playing groups and staff of the Adelaide, Port Adelaide and West Coast football clubs.

"We will provide all the necessary support through the services we currently have in place."

Walsh was a former player in the Victorian Football League in the 1980s, pulling the boots on for Collingwood, Richmond and Brisbane during his playing career.

Walsh recently made the headlines after famously comparing the Crows’ “frustrating” results in 2015 to the turmoil endured by famed artist Vincent Van Gogh.

He mostly played as a wingman.

Following his retirement as a player, he joined Geelong as a strength and conditioning coach before being appointed assistant coach at Port Adelaide in 1999.

He left to become an assistant coach with the West Coast Eagles in 2009, before returning to Port Adelaide in 2014.

Later that year, he was appointed the head coach of the Crows on a three-year deal.

Walsh had previously said he had never sought a senior coaching position, but a near-death experience in Peru in 2012 forced him to examine what he wanted for a future.

The entire AFL community has rallied around the Crows, with Mr Chapman welcoming news that even Port Adelaide – the Crows’ crosstown rivals – scarves had been left outside the club with messages of condolence and solidarity.

Cy Walsh remains in a mental health ward in Adelaide tonight. (9NEWS)