Raiders back to just 3 QBs as Peterman to IR

Orlovsky: What if having 4 QBs is a smart move? (0:53)

Dan Orlovsky questions whether or not the Raiders having four quarterbacks on their roster is a smart move. (0:53)

ALAMEDA, Calif. -- Well, that was one way to keep Nathan Peterman in house while keeping three quarterbacks on the 53-man roster.

The Oakland Raiders placed Peterman on injured reserve with a reported elbow injury on Monday, a day after the team claimed DeShone Kizer off waivers from the Green Bay Packers.

The Raiders also placed rookie cornerback Isaiah Johnson, who suffered a concussion in the preseason opener, on IR and re-signed defensive end Josh Mauro and linebacker Kyle Wilber.

As it stands now, the Raiders have three QBs in starter Derek Carr, Mike Glennon and Kizer.

"I'm a big believer that you've got to take care of that position," Raiders coach Jon Gruden said. "Kizer's a guy that I liked coming out of Notre Dame, he's only 23 years old, he's got 15, 16 starts, started two games in the preseason this year for Green Bay. So, he's had a lot of reps, he's had a lot of experiences. I'm sure most of his bad experiences, like Peterman's, will be reported over and over.

"But I think he's got a big upside. He's athletic ... we've got to fast-track him. He's got a lot to learn in a short period of time but we are really disappointed that Nate got hurt."

Gruden said Peterman injured his elbow in the preseason finale at Seattle on Thursday.

"He actually finished the game," Gruden said. "He came over on the sideline, sore right elbow, and after the game it got a little bit more sore and we gave him the MRI and there was a little ligament problem there. He won't have to have surgery. Probably be back middle part of the season so we need a quarterback that can move around and emulate (Patrick) Mahomes and Deshaun Watson, and Peterman was going to do that for us, zone-reads, all the things that he's able to do, and now Kizer gives us a dimension that will help us prepare for opponents and we think he's got some upside in our system."

There had been speculation that Oakland was not going to cut either Glennon or Peterman a week before facing a QB-needy team in the Denver Broncos, lest they sign one of them and dive into the Raiders' offensive game plan.

With Peterman on IR, that is now not a possibility. Having been on the initial 53-man roster, Peterman is eligible to be on short-term IR, though it is unlikely he would return with three QBs ahead of him.

Gruden kept only two quarterbacks last season in Carr and AJ McCarron. McCarron was about to replace a beat-up Carr against the Seahawks in London in Week 6, but Seattle ran out the last 8-plus minutes of the game.

"We went down to one quarterback last year (and) I almost jumped off the bridge," Gruden said. "You have to shut down business if you don't have a backup quarterback. My brother went through it last year (in Washington).

"Some franchises go with two -- they've had a guy that's stayed healthy for 10 years. And I hope Derek does that. This is no reflection on Derek but I just think you've got to have guys developing at that position, you've got to have guys ready to go out and play."