Port Adelaide chief executive Keith Thomas said the Power had 'great hopes' for John McCarthy before his tragic death on Sunday morning (US time) in Las Vegas.
McCarthy crossed over to Port Adelaide at the end of last year after limited opportunities in four frustrating seasons at Collingwood.
And the 22-year-old had an immediate impact with his new club this season, averaging 19 disposals across 21 matches.
But tragically, his full potential will now never be realised after he fell from a building to his death in the world-famous gambling city.
"He was a fantastic young fella, well liked, he was a terrific fella," a devastated Thomas said at Alberton on Monday.
"He came into the footy club looking to reignite his career, he played 21 of the 22 games this year, he started like a bomb and looked fantastic.
"We had great hopes for him and it's so disappointing on a football front but more on a personal front."
Thomas described McCarthy as a very popular player who immediately fitted in at the club.
"John was a very popular Port Adelaide player and had embraced the club as we had embraced him and ours thoughts and prayers are with his parents and his family right now," Thomas said.
McCarthy flew out to Las Vegas on Saturday morning with 10 team-mates for a holiday that was set to last seven to 10 days.
He travelled with Port Adelaide team-mates Travis Boak, Matthew Broadbent, Alipate Carlile, Brett Ebert, Hamish Hartlett, Tom Logan, Andrew Moore, Paul Stewart, Jackson Trengove and Justin Westhoff.
Thomas said they took the news very hard.
"(It's been) very, very tough (on them), I was on the phone with them when we let them know the news, they weren't with John at the time, it was a great shock," Thomas said.
"(They were) very emotional and they are making arrangements to come back now."
And the news wasn't any easier on McCarthy's fellow Power players back home who, along with staff, are being provided with grief counselling.
"We held a whole-of-staff meeting with the players, there were tears, he's a popular young fella," Thomas said.
Thomas described McCarthy's death as a major emotional setback for Port Adelaide but vowed the club would be stronger for the tragedy.
"It's devastating news, it's a young fella, he's 22 years old, we endured a tough year on the field, we were in the process of looking forward to next year and this is a major, major setback emotionally but we'll come through it," Thomas said.
"The first thing is to make sure everyone is OK, that his parents are looked after and his brother and his sister.
"We'll wrap our arms around our players and their partners, we're doing that now, and we'll be stronger for it."
The accident involving McCarthy happened at a different hotel from where he and his team-mates were staying at.
Thomas said the matter was still being investigated by local authorities.
Port Adelaide football operations manager Peter Rohde has flown to America to help McCarthy's family bring his body back home.
AFL CEO Andrew Demetriou extended his condolences to McCarthy's family, friends and Port Adelaide.
"This is a terrible tragedy for John's loved ones and our deepest sympathies go out to them," Demetriou said.
"It is a very sad day for the Port Adelaide Football Club and the rest of the AFL industry to lose a young man in the prime of his life."
McCarthy's former club Collingwood have also been left reeling by the terrible news, with Magpies president Eddie McGuire and captain Nick Maxwell expressing their sorrow.
"This tragic news has come as a shock to everyone at the Collingwood Football Club," McGuire said.
"John was an exceptional young man in the prime of his life with the whole world ahead of him.
"We are proud that John wore the black and white jumper and his contribution to our club will never be forgotten."
Maxwell added: "J-Mac was a great mate to a lot of us. He was a gutsy team-mate and wonderful person.
"It's a terrible day, a devastating day. Everyone here, especially his closest friends, feel for the McCarthy family."Our thoughts and deepest sympathies are with them as we all bind together during this time. Today we lost a great friend."