He is not one tiny bit less emotional though, and when Angus Brayshaw made his way back into the Demons' team again four weeks ago, he couldn't help but feel warm and fuzzy inside. The No.2 and the No.3 draft picks in red and blue together, for the very first time.

Petracca was away from the club when Brayshaw was picked to play, but made sure to mark the occasion by tweeting him. Brayshaw got back to him straight away: it was going to be the first joint effort of many.

Then Max Gawn interjected, wondering why they couldn't have had their conversation in the change rooms.

"It was good timing, and he got us," said Petracca.

"Even he didn't think it would get so many retweets and likes though. He thought it would get a few hundred and it's on 1000 now. I checked it last night, and he liked it himself to get it up to 1000."

Petracca didn't think it would take a season-and-a-half for him and Brayshaw to line up in the same side.

He didn't assume he would walk straight into the Melbourne team when he was drafted there at the end of 2014. But it was what he wanted badly, what he was driven to do and what he expected of himself, deep down.

Instead he had to spend all his days in the gym, rehabbing the knee, watching Brayshaw get started without him.

So much energy; nowhere for it to go.

"I was pretty jealous of him last year, to be honest," said Petracca.

"Watching him play and doing really well, I just wanted to be out there and it sucks sitting in the stands.

"It went by real quick, but it was a pretty frustrating year having to watch all the time. There's no better feeling than playing now, though.

"I love being out there so much. Last year I was always thinking 'What would it be like, how would I go, what would I be doing'?

"And it's way better than I thought."

It still is for Brayshaw, too. Last year he played in almost every match. Nothing, really, went wrong.

Then he hurt his knee five seconds into Melbourne's first pre-season game this year, missing matches for the first time because of an injury.

Then he came back a little too heavy, struggling to run, and was sent back to the VFL. There, he got concussed.

Then he got knocked out again. It was six weeks before the medical staff felt he was ready to play again, and before he felt sure in his own mind they were right.

Spending two weeks in bed, suffering with headaches, nauseous and just not right, was one thing. Getting back to doing the things that had always come so instinctively was another challenge entirely.

"It's hard to explain concussion but after the second one I just felt terrible. I stayed home lying in bed and physically I just couldn't do anything at all. The club was really good in how they incrementally stepped me up, but it was more of a mental thing in the end," Brayshaw said.

"Christian found the same thing with his knee – every step up that you take coming back is like another step into the unknown of your recovery.

Every time the ball got near me or there was a contested situation I was like, 'Oh god, is this going to happen again'?"

Brayshaw spent some time with the club psychologist, Dave Williams, which helped.

"It helped a lot, he was really good and since I've got back into playing I haven't really thought that way at all," he said.

"At first I think it came about because I'd been running and doing conditioning stuff, but none of it had involved contact, so when contact came into it I started having all these thoughts I'd never had before.

"It was running through me, thinking, 'Oh no, that's a contest, I could get hit'.

"And, 'If I get hit, will this happen or that happen'? I kept thinking I was going to have my head taken off every time the ball was near.

"I was second-guessing myself, absolutely, and having doubts. Dave really helped me start to recognise when that was starting to happen, and to chill myself out, and I'm all good now. I feel really good. When I came back, I was ready."

So was Petracca. He was really, really ready. The first time he thought he had a real chance of getting into the senior team was ahead of Melbourne's Anzac Day Eve match against Richmond; before the Demons started training for the last time before the game, coach Paul Roos told him that if Jeff Garlett and his sore ankle didn't make it safely through the session, he would be making his debut under lights at the MCG.

It was a strange session – so everyone told him. "Roosy said 'You're only playing if Jeffy drops out', so I was like 'Ohhhhh, all right'. So for the whole session, everyone was taking the piss out of me," Petracca said.

"That's because you were watching Jeffy the whole time," said Brayshaw.

"I was not watching him!" said Petracca.

"They were telling me I was staring at him, but I wasn't, and Jeffy kept coming near me and bumping me, so his ankle was obviously fine.

"It was the biggest anti-climax. It was like, 'I'm a chance here, I'm going to be playing Anzac Eve'.

"And the way Jeff was training, he looked terrible. But Jeff's Jeff, he got up and in the first quarter he kicked three and had 10 possessions and was a star.

"But that was all right, then the next week Roosy told me I was in for sure and I didn't have any idea how to express myself. I went home and almost started crying, to be honest. I don't how I didn't. It was the most awesome feeling ever."

Petracca hasn't missed a match since, and has learnt so much before, during and after each one.

He knows why he had to do all that core work, having wondered at first how on earth it would help his knee get better. He understands all the little things he does every day will help determine how he feels and plays on the weekend.

He knows you can't partake in pre-season dunking contests against your dog, because you'll fracture your ankle and make your coach extremely unhappy. And he knows how much bigger a part of the team you feel when you're out there on the ground, playing.

"How do I describe it? It's just that you build a lot more friendships on the field, from being out there trying to help the team win," he said.

"I was a little shit when I got to the club and people didn't really know my personality, so they would get sick of me quite often, but now I think they like me a bit more.

"When you get to a team you just need a bit of time to get to know everyone and for them to get to know you. I didn't realise how much just playing would help make that happen. It's been so good."

Brayshaw has a new appreciation for that too. Now that he is back in a team he hopes he, Petracca and a whole lot of other new Demons will play a lot of games, over many years.

"We've had so many young players come in over the last few years and the coaches are developing us well," he said. "We're being taught the right stuff and hopefully that's something that will help a lot of us be here together for a big amount of time."

Petracca agrees.

"We're all really competitive, the two of us, and everyone else here as well," said Petracca.

"We wouldn't be here if we didn't want to compete with each other.

"In the pre-season we just want to be the one who wins, but in the season all we want is the best for each other and the thing we all want is to win."