Leslie Frazier couldn't stop smiling during his weekly news conference on Monday when he touched on watching the game footage from the Vikings' 48-30 victory over the Eagles on Sunday.

The Vikings coach specifically pointed out the reserves that played well in the absence of cornerbacks Xavier Rhodes and Chris Cook, and running backs Adrian Peterson and Toby Gerhart. Matt Asiata and Shaun Prater each got their first career starts, with Asiata rushing for three touchdowns and Prater intercepting a pass.

Frazier credits the coaching staff for developing some of the young players for that opportunity. The reserves typically stay after practice with the coaches to receive extra reps they normally wouldn't receive in practice or in a game.

"We tell them all the time things can change in a hurry in the National Football League where you go from not dressing to all of a sudden having to be a starter in a ballgame," Frazier said. "We'll keep them after practices and the coaches will work with them."

Healing quickly

Frazier expects most of the players who were inactive against Philadelphia to return Sunday at Cincinnati. His biggest concern, however, is Rhodes (ankle). Tight end John Carlson (concussion) was evaluated Monday, but Frazier said he didn't pass the NFL concussion protocol over the weekend.

The biggest inactive surprise was Cook, who was added to the injury report Friday after tweaking a knee in practice. Frazier said it happened when he was planting on a route. An MRI revealed that Cook had a bone bruise but didn't structurally damage the knee.

"[It's] more of dealing with the things you have to do as a defensive back — plant and turn without thinking; you can't be worried about the pain," Frazier said.

"The fact that he was having trouble planting and driving, getting out of his back pedal, that's a problem as a defensive back."

In his first career start, Prater got that interception — something Cook hasn't accomplished in four seasons with the Vikings. Cook, who will be a free agent in the offseason, has yet to play a full season because of injuries and a suspension.

"You can have talent, but if you're not available, that kind of negates everything that you're trying to get done as a player, and it really makes it tough for your teammates as well," Frazier said. "I know he's trying to get out there."

Out for the season

Cornerback Josh Robinson was placed on injured reserve Saturday because of a fractured sternum he suffered in Week 11 against Seattle. Robinson thought he had a chance to practice last week, but the injury didn't heal as quickly as expected.

"We needed to get some other guys up, and he's one of the guys that we didn't think was going to make it back, where initially we were hoping that he would," Frazier said. "It wasn't going to work out."

Robinson said he had a follow-up CT scan that didn't show a setback.

"I've always recovered from injuries quite fast; I can usually push through anything, but it was really just being smart," Robinson said of going on injured reserve. "Not just going out there and risking it or getting worse to something significant."

Etc.

The Vikings re-signed offensive tackle Mike Remmers, who was waived Saturday because of the lack of depth at running back and cornerback. They waived running back Joe Banyard, who was activated off the practice squad and played Sunday.