The 23-year-old, who signed a two-year rookie international rookie contract in October, was confirmed as a Saints player on Wednesday in the NAB AFL Rookie Draft.
He was mid-air on the way to Boulder, Colorado, for the Saints' altitude training camp when his name was read out after the club confirmed Maverick Weller and Eli Templeton as their other rookies.
Having been training with the club since the start of its pre-season, Holmes has thrilled coaching staff and the players with his potential, and dramatic improvement when it comes to ball handling.
"We've been delighted with the three weeks he's been at the football club with just how much he's improved his skill base in that short period of time through having daily access to skills training," head of football Chris Pelchen told AFL.com.au.
"I think it's surprised most of our players just how athletic he is for a guy who's 202cm.
Saints sign US giant
"While in American sport, particularly in basketball, we see guys of that height playing with that type of prowess regularly, it's still somewhat rare at AFL level to have someone with the degree of agility that Jason has.
"It's something that's certainly impressed not only our coaches but our players as well."
Holmes, who played college basketball for Morehead State Eagles in Kentucky, spent three weeks with the Sydney Swans Academy under Paul Roos earlier this year.
After initially being identified at the April AFL Combine in Los Angeles, he impressed again at the October Combine at Etihad Stadium.
He recorded a vertical leap of 97cm, which was just four short of high-flying West Coast ruckman Nic Naitanui's record.
Now, just over six months after he picked up the game, he's accelerating his development in Colorado with his new teammates in the tough high-altitude environment.
"I know it's going to help me in the long run. I know I've got a long way to go as far as cardio and skills, so it's going to be huge for me," Holmes told the club's website.
"I'm learning with the best, and the speed at which we're training … you don't have time to think, you just have to react.
"It is getting a little better, even just with lane kicking, just taking a mark and kicking to a target.
"There's not much thinking about it; you just have to do it. It's getting better."
The Saints will be patient with their tall prospect, who has been earmarked as a ruck/forward option and has used Aaron Sandilands as an example of the type of player he wants to emulate.
He is expected to start with Sandringham in the VFL in round one, where his athletic ability will be on show as he develops skills that players around him have possessed for much longer.
But, Pelchen – who believes the US is a natural extension of AFL development after the League's forays into Ireland and New Zealand – thinks Holmes will continue to make rapid improvement when he starts playing.
"We don't have great expectations on him in the early part of the season, but having said that, because he is from an athletic background, we expect that he'll pick up the skills of AFL football more quickly than a player coming from a lower base," Pelchen said.
"I think we all appreciate Jason is coming from a very different background in terms of AFL football and that's acknowledged by everyone in the AFL industry.
"He's really only been familiar with AFL for the last six months and we were all impressed with not just talking to him but watching his application on the training track.
"We felt that he was worth an opportunity."
Twitter: @AFL_JenPhelan
"While in American sport, particularly in basketball, we see guys of that height playing with that type of prowess regularly, it's still somewhat rare at AFL level to have someone with the degree of agility that Jason has.
"It's something that's certainly impressed not only our coaches but our players as well."
Holmes, who played college basketball for Morehead State Eagles in Kentucky, spent three weeks with the Sydney Swans Academy under Paul Roos earlier this year.
After initially being identified at the April AFL Combine in Los Angeles, he impressed again at the October Combine at Etihad Stadium.
He recorded a vertical leap of 97cm, which was just four short of high-flying West Coast ruckman Nic Naitanui's record.
Now, just over six months after he picked up the game, he's accelerating his development in Colorado with his new teammates in the tough high-altitude environment.
"I know it's going to help me in the long run. I know I've got a long way to go as far as cardio and skills, so it's going to be huge for me," Holmes told the club's website.
"I'm learning with the best, and the speed at which we're training … you don't have time to think, you just have to react.
"It is getting a little better, even just with lane kicking, just taking a mark and kicking to a target.
"There's not much thinking about it; you just have to do it. It's getting better."
The Saints will be patient with their tall prospect, who has been earmarked as a ruck/forward option and has used Aaron Sandilands as an example of the type of player he wants to emulate.
He is expected to start with Sandringham in the VFL in round one, where his athletic ability will be on show as he develops skills that players around him have possessed for much longer.
But, Pelchen – who believes the US is a natural extension of AFL development after the League's forays into Ireland and New Zealand – thinks Holmes will continue to make rapid improvement when he starts playing.
"We don't have great expectations on him in the early part of the season, but having said that, because he is from an athletic background, we expect that he'll pick up the skills of AFL football more quickly than a player coming from a lower base," Pelchen said.
"I think we all appreciate Jason is coming from a very different background in terms of AFL football and that's acknowledged by everyone in the AFL industry.
"He's really only been familiar with AFL for the last six months and we were all impressed with not just talking to him but watching his application on the training track.
"We felt that he was worth an opportunity."
Twitter: @AFL_JenPhelan
