WHEN the Sydney Swans selected Alex Johnson with pick No.57 in last year's NAB AFL Draft, he was viewed as a long-term project.

There was undoubted talent, but Johnson was a "tall and skinny kid" who had spent most of his junior years as a forward, while the Swans wanted to use him in defence.

He also had a long road ahead getting himself physically ready for senior football.

"We looked at his body and thought it's going to take him a couple of years to develop," Swans coach John Longmire said.

Johnson himself wasn't even certain he was going to be drafted, but there was an inner drive in the Oakleigh Chargers product that if he was given a chance, he wouldn't let it out of his grasp.

Draft night then turned Johnson and his family's world upside down.

"It was a pretty surreal experience," he said.

"A few people asked me in the lead-up to the draft 'do you think you'll get picked up?', and I never really gave them a definitive answer.

"I was happy with how my year went last year, but you never really know. It's a bit of (the) luck of the draw and what teams want.

"I watched the draft with mum and dad, and when Sydney called out my name I was excited.

"I was sad to be moving away from Melbourne, but mostly excited just to find myself on an AFL list and get my foot in the door

"I always said the most important thing was to get your foot in the door, and where you go from there is up to you."

It was that attitude that led to Johnson playing in the senior side months, or even years, before anyone expected.

The first task was to put on weight and get his body ready.

"That was a massive focus over the pre-season," he said.

"I put on about 10 kilos in the three or four months that I was here in the pre-season.

"I stacked it on pretty quickly, I was spending a lot of money on food and doing seven or so sessions a week in the gym, which was something I wasn't used to."

It took Johnson to his current weight of 88kg and at 193cm, he now has the size to hold down a key position.

After just two practice matches with the reserves, seconds coach Henry Playfair told Johnson to start preparing himself for the possibility of a senior call-up.

One week later, he was in the team for the Swans' round three clash with West Coast at Patersons Stadium.

Johnson was shocked by the news, although the coaching staff managed to lighten the mood with a joke about the Eagles' 2010 draftee Jack Darling.

"John (Longmire) called me with all the other coaches on speaker phone and they were having a bit of a laugh in the background," Johnson recalled.

"They played a bit of a joke on me. They asked if I had played on Jack Darling in the nationals, and said they heard he towelled me.

"I wasn't too sure what to say.

"Then John just asked me if I wanted a trip to Perth, and I said I'd never been to Perth before. I was in shock mostly and then straight on the phone to mum and dad. They couldn't believe it."

Once he got to Perth, Johnson sure wasn't laughing when he went onto the ground for the start of his first game.

"We thought the ideal match-up would be me on Jack Darling, but he started on the bench," he said.

"So I walked out to the backline and the only free player was Quinten Lynch.

"He's got about 20 kilos on me, and it was a different experience playing on someone like that."

While Johnson is preparing for his 11th game against Gold Coast this Saturday, the 19-year-old admits that at this stage of the year he thought he would still be waiting for his first.

Instead, he has only missed two games since his debut, and both were due to slight injuries.

"Alex Johnson's just been a real surprise for us the way he's developed," Longmire said.

"He's such a competitor. He's able to play on smalls and talls. He's been enormous for us down back.

"He's a wonderful athlete, he's quick with great endurance and then he attacked the gym really well and put on some size.

"There was no way at pick 57 when he turned up we thought he would've developed this quickly. We've just been rapt with the way he's gone."