Returning prodigal son Trent Merrin says he's noticed a "calmer" Paul McGregor since he played under the coach at the Dragons in 2014.

Talking to Big League for the 2020 Season Preview, Merrin says the new coaching structure at the club, which included the signings of Shane Flanagan and James Shepherd, have had an impact on their mentor and the team.

"I've seen a lot of change in Mary since I was last here," Merrin says. "He's calmed down and it's great to see he's trusting the coaches around him because that stuff seeps through to the team.

"He's got a playing group here who believe in him.

"A lot of things happened here last year that you couldn't control - injuries and off-field stuff - but you can see that he trusts everyone and we're reaping the rewards from that. He's definitely grown over the years."

Merrin is one of several local juniors who will be taking the field for the Dragons in 2020, something he thinks has also changed the vibe around training.

"It's not just about talent, it's about passion. When you come through the grades and come through the local area, this place becomes your home and it's where you're most comfortable," he says.

Match Highlights: Knights v Dragons

"I know when I was a junior, all I wanted was to play for the club. To get the chance to pull on the Red V for the first time meant the world to me, and that's the passion you get from local juniors that go through the same journey."

Read more about each NRL club's preparation for 2020 in the Big League Season Preview, available and newsagents, supermarkets and magsonline.com.au/big-league-2020-season-preview