AFL club Port Adelaide is no wiser about how footballer John McCarthy died at a Las Vegas hotel.

A distressed McCarthy is understood to have told his girlfriend he wanted to return home just hours before falling nine metres to his death at the Flamingo hotel.

He is understood to have told his girlfriend he was heading to the airport after becoming separated from his Port Adelaide teammates on an end-of-season trip to the US.

As the Las Vegas coroner says there doesn’t appear to be any suspicious circumstances surrounding the 22-year-old’s death, executives of his club Port Adelaide remain puzzled.

“We do not have a lot more information about the events that led to John’s death,” Port CEO Keith Thomas said in a statement on Tuesday.

“US authorities have confirmed that John died after falling approximately nine metres from a building after becoming separated from his teammates.

“We are no clearer about how or why that happened.

“There are media reports of a phone conversation between John and his girlfriend Dani in Adelaide. We are aware a call was made but we will not speculate or comment further about that conversation.”

Clark County coroner Mike Murphy said McCarthy fell about nine metres from a roof at the Flamingo and that there were no signs of any foul play.

“There is nothing that indicates this is a homicide so now we’re investigating this as either an accident or a possible suicide,” Mr Murphy told AAP on Tuesday.

The coroner stressed that he was not saying McCarthy’s death was a suicide.

The death was being investigated, he said.

McCarthy was found on the driveway of the hotel at about 5.40am on Sunday, Las Vegas time – some four kilometres from the hotel where he was staying.

An autopsy has been completed, but it would take at least eight weeks before results from toxicology tests on McCarthy were known.

McCarthy telephoned his girlfriend Dani Smarrelli in Adelaide, sounding confused and saying he wanted to return home, Smarrelli is understood to have told Port officials.

His 10 teammates in Las Vegas were unaware he had died until informed by Port officials hours after the fatality.

McCarthy left Collingwood, where he played 18 games over four seasons, late last year and joined Port Adelaide, where he played 21 games this season.

New Carlton coach Mick Malthouse paid tribute to McCarthy, whom he coached for four years at Collingwood between 2008 and 2011.

“It’s one of those moments where you come to realise being an AFL footballer doesn’t give you an immunity to tragedy,” Malthouse told reporters in Melbourne on Tuesday.

The AFL said there would be a minute’s silence before each of this weekend’s semi-final matches as a mark of respect for McCarthy.