As Mike Zimmer surveyed his rookie class on Thursday, running through the list of his first-year players at a reporter’s request, the Vikings coach could tick off players who were already key contributors, important role players or promising prospects.

“[Pat] Elflein’s pretty good. [Dalvin] Cook is good,” Zimmer said. “[Ben] Gedeon’s done good. We’ve got a lot of them, right? I think [Stacy] Coley’s going to be a player. [Rodney] Adams, he’s got a chance to be a player. [Jaleel] Johnson, he does, too.”

That’s a far cry from a year ago, when a roster decimated by injuries was still unable to ask for much from a rookie class bereft of immediate contributors. This season, in a year in which the Vikings knew they were going to have a younger roster after letting some veterans go, their rookies have been more than capable of filling in the gaps.

Vikings rookies already have logged 1,388 snaps on offense and defense this season, led by Elflein’s 837. The third-round pick, who figures to return from a shoulder injury on Sunday, has played 91.9 percent of the Vikings’ offensive snaps at center and could be in line for All-Rookie Team honors at the end of the season.

Cook appeared on his way to plenty of accolades, too, before tearing his ACL in Week 4. He has a good shot to return in 2018 as the Vikings’ featured running back. Gedeon has started seven games as the Vikings’ weak-side linebacker, and fifth-rounder Danny Isidora made a spot start at left guard on Oct. 29.

“Some of those guys you’re talking about — Elflein, Gedeon, Cook — are some of our more important guys,” Zimmer said. “I think some guys just take longer than others.”

The Vikings have certainly seen their 2016 class take a more circuitous route.

At this time a year ago, Laquon Treadwell had already played the final snaps of a rookie season in which he caught one pass. Second-round pick Mackensie Alexander had already seen the largest number of defensive snaps (18) he would receive in a single game. The Vikings, who had cut fourth-rounder Willie Beavers in training camp, had brought him back in a tireless search for offensive line help.

Fifth-rounder Kentrell Brothers and sixth-rounder David Morgan had carved out roles mostly on special teams, but seventh-rounder Jayron Kearse’s brief turn as a starting safety ended with a missed tackle on Jordan Howard’s 69-yard run in a Nov. 1 loss to the Chicago Bears.

The group, as a whole, played just 301 offensive and defensive snaps in 2016 — the lowest of any rookie class in the league last season. That came on a team stocked with veterans, a year after the Vikings’ impressive 2015 draft class logged 3,299 snaps as rookies. And as the 2016 team set its sights on a deep playoff run with a roster composed of established players, it leaned toward drafting developmental players who might need more time.

Some of those players have started to show progress in Year 2, with Treadwell catching 17 passes and Alexander playing 34.6 percent of the Vikings’ defensive snaps while sharing the nickel cornerback role with Terence Newman. Morgan has become a reliable run blocker who could see plenty of playing time on Sunday with Kyle Rudolph doubtful, and seventh-round pick Stephen Weatherly has seen some brief stretches of playing time at defensive end.

The 2016 group still might not have any players as integral to the Vikings’ plans as Elflein or Cook, and it remains to be seen how the team’s sophomore class will pan out. The 11-member draft class of 2017, though — not to mention undrafted free agents who made the 53-man roster, such as defensive end Tashawn Bower and tackle Aviante Collins — already has yielded three starters, with the potential for more contributors down the road.

And if you’re looking for reasons why a team that looked listless in its most lopsided defeat of last season — a 38-7 loss to the Indianapolis Colts — has a chance to clinch the NFC North exactly 52 weeks later, the Vikings’ successful, and important, infusion of youth should be among them.