Highlighting the performances of ruckman Hamish McIntosh and utility Leigh Harding in Sunday's 34-point win over Melbourne, Simpson said second-tier of players would be crucial to the Roos' fortunes this year.
Their importance will swell as soon as this week when North meets 2008 preliminary finalists the Western Bulldogs at the MCG.
"They're up and about, aren't they?" Simpson said of the Dogs from Arden Street on Tuesday.
"I thought they might have been a little bit underdone going over to Fremantle, but they were probably the most impressive team of the weekend. It's such a quick running style that they've got.
"They've got a really good even spread through their midfield and that's what we're aiming for as well. We need Mick Firrito and Leigh Harding and even young Gavin Urquhart pushing up on a wing – those types of players doing their job.
"Obviously Hamish on the weekend had a great game and we're looking forward to him backing that up and having a really good year."
Simpson said Harding, who had 28 possessions and seven tackles against the Demons, was capable of taking his game to another level after playing a lot of last season at half-back.
Spending the early stages of his career as a small forward, Harding was sidelined for most of 2007 with a knee reconstruction but has re-invented himself in his return.
"There were glimpses last year," Simpson said. "One particular game against Carlton I think he kicked two or three on (Chris) Judd running through the middle. He had the potential to come up.
"He's a mature body now and he's one of those guys I anticipate to play 200 or 250 games. I think on the weekend he just proved to people on the outside what he's capable of.
"If he has one of those games every week he'll have a pretty good year."
However, a strong start to the season for some could work against midfielder Daniel Harris, forward Corey Jones and defender Shannon Watt.
Despite more than 400 games' combined experience, the trio remained on the cusp of selection for round one but should press for opportunities this week.
Simpson said they were upbeat.
"I think it just shows we've got a healthy list at the moment," he said. "They're all fully capable of playing senior footy. Benny Ross was right up there as well.
"Everyone's feeling the pressure that you've got to play well to hold your spot.
"Probably the biggest thing you miss when you're not playing seniors is you're just not with the players during the week and obviously you're not playing on the weekend.
"You do feel a little bit out of it. All of them have been really good with their attitudes and their time will come."
Sunday's clash with the Bulldogs will recognise members of the Victorian State Emergency Services and North hopes for a crowd of 60,000.
