Matthew Johnson has reflected on the guidance of retired Fremantle great David Mundy, who helped instil belief in the 20-year-old across his first year in the AFL system.

Johnson learned of his debut in a Friday morning team meeting, named as the tactical substitute for Sunday’s RAC Derby clash with West Coast at Optus Stadium.

The 193cm and 84kg midfielder already boasts significant size, and has earned comparisons to Mundy, even from the Freo legend himself.

“Dave was pretty good at helping me believe in myself and my ability,” Johnson said.

“He always reinforced for me to back myself in and play to my strengths - so to have had that older head to go to for some advice was super beneficial.

“One of my mates sent (Dave’s comparison comments) through and I was pretty rapt to hear Dave say that.

“He has been a great player for a long period of time - so I have got a fair way to go to reach his standards!”

Johnson said the initial rection to the news was one of relief and shock, expressing his pride in being surrounded by his teammates for the special moment.

He said the opportunity to debut in an RAC Derby had added an extra layer of significance.

“I’m pretty relieved and overwhelmed… it was good to have that announced in front of the boys and have them all get around me. I felt pretty lucky,” Johnson said.

“JL just went through the squad and got to my name, and it was the first time I heard that I was playing.

"It will be exciting to be out there playing in one.”

Johnson acknowledged the significant midfield depth at Fremantle, praising his more experienced teammates and the Club’s coaching staff for their teachings.

“We have got a pretty strong list as it stands at the moment…(it’s been good) to learn off them and develop my craft at Peel and get better personally,” Johnson said.

“It makes it mean a little bit more…the coaching staff and people behind the scenes think I am ready to step out there and perform, so it gives me a little more confidence knowing they have got that faith in me.”

Johnson becomes the 240th player to pull on the Fremantle jumper in the AFL, and the first to make their AFL debut this season.

In an ironic twist, Johnson’s 2021 draft mate in Neil Erasmus also debuted in an RAC Derby in the exact same round of last season.

A whole block of Optus Stadium seemed to be filled with Erasmus’ closest mates for his debut game, with Johnson hoping to replicate the same level of crowd support.

“Hopefully, I can get a few of the boys down, they are all pretty keen,” Johnson said.

“If I could get 100 tickets I’m sure I could fill them all.

“I have got a pretty loyal group of friends so I am sure they will all be there supporting me.”