"People don't understand the relentless nature and how tough it is for these young men.
"At the moment, young players, sometimes they come in and out and that's the nature of it."
McFadden understands the high calibre of raw talent at his disposal and insists he has a good and accurate gauge of how they are tracking week to week.
Rookies may burst on to the scene riding a wave of confidence and enthusiasm over three or four matches before concentration lapses and mental and physical fatigue begin to creep in.
Lisone, Vete, and Maumalo have all taken their games to a new level this season after battling inconsistency last year. The trio made strong impressions through their initial appearances in 2015 but slipped off the pace as the season wore on.
Even James Gavet, a veteran by comparison in his fifth NRL season, has had his ups and downs this year, starting off the campaign in first grade before a drop in intensity saw him relegated to NSW Cup for a prolonged stint.
"They're very young and all of these guys are all less than 30 or 40 games into their career," he said.
"Most coaches will tell you you're not really a first grader until you're above 50 or 100. That's when you really start to understand the game.
"They're still very talented and doing a great job, but I get to see them seven days a week and see their energy levels and understand how they're feeling emotionally, and that's certainly factored into my decision making when I pick the team.
"With young guys it's really important to manage their energy. It's tough to get them up for every week and certainly their enthusiasm is great when they come in.
"But the hard part about this game is the week to week relentless nature of the competition. That's tough for young players."