Four rookies started on defense for the Vikings last night, and three of them were making the first start of their career against the Cardinals.

Undrafted rookie safety Anthony Harris made his NFL debut in the 23-20 loss and played all 67 defensive snaps. He was forced into the lineup after four Vikings safeties suffered injuries in the two previous games.

The Vikings also moved veteran cornerback Terence Newman to safety, which allowed them to give first-round pick Trae Waynes the first start of his career. Waynes played a career-high 61 defensive snaps, which was as many as fellow starting cornerback Xavier Rhodes. Newman, meanwhile, played 64 snaps, the majority of them at safety.

With outside linebacker Anthony Barr sidelined, seventh-round pick Edmond Robinson replaced him at strong-side linebacker in the base defense. Since the Cardinals opened the game in a two-receiver set, he played the first snap and was credited with his first start. He would play 26 snaps in the loss. It was Robinson's first action on defense all season.

The other Vikings rookie to start on defense was middle linebacker Eric Kendricks, who remained in his every-down role, playing all 67 snaps. Fellow linebacker Chad Greenway also played every snap with Barr out.

Third-round pick Danielle Hunter did not start against the Cardinals, but the rookie defensive end had a significant role again with 28 snaps.

Here are some other observations from the NFL's official snap counts:

— Rookie wide receiver Stefon Diggs, a fifth-rounder pick, played all 68 snaps on offense. That is the first time a Vikings wide receiver didn't take a breather in a game all season. Fellow starter Mike Wallace played 58 snaps. Slot man Jarius Wright played 39. And Adam Thielen got 13 while Charles Johnson and Cordarrelle Patterson did not see the field on offense.

— Defensive tackle Tom Johnson got another start and played all but six snaps, an uncharacteristically high snap total for a Vikings defensive tackle. Sharrif Floyd, who again started at nose tackle in place of the injured Linval Joseph, played 48 snaps. Backup tackle Kenrick Ellis played 14.

— Defensive back Shaun Prater, who was signed off the street on Tuesday, played seven snaps in his return to the Vikings. That was one more than Robert Blanton, who played despite his knee injury but did not start.

— Four days after he grumbled about his role in a loss to the Seahawks, running back Adrian Peterson dominated the backfield playing time with 56 snaps, and he rushed for 69 yards on 23 carries. Matt Asiata got seven snaps and Jerick McKinnon got five. Fullback Zach Line got just six, but he made an impact with an impressive fourth-quarter catch and run.

— Tight end Kyle Rudolph played 57 snaps and led the Vikings with six catches and 67 receiving yards. Backups Rhett Ellison and rookie MyCole Pruitt, another fifth-rounder, played 26 and five snaps, respectively.

— Defensive end Everson Griffen played 61 snaps in his return to his home state. Fellow starter Brian Robison played 55. And backup Scott Crichton got three snaps on defense before exiting the game with a concussion.