It was no secret the Cardinals wanted to add a big running back in the NFL draft. The question was who it would be.

On Friday night, the answer came. Northern Iowa's David Johnson was the Cardinals' third-round selection, giving coach Bruce Arians another backfield option to pair with Andre Ellington.

Johnson is listed at 6-foot-1 and 224 pounds. He averaged 5.6 yards per carry and scored 49 rushing touchdowns over his four-

year career and could be counted on for short-yardage looks. But Johnson isn't just a bruiser, as he ran a 4.50 40-yard dash at the NFL Scouting combine and is noted for his receiving ability after playing wideout in high school.

"Something that a lot of teams don't really look into with bigger running backs is my ability to catch out of the backfield," Johnson said. "Being utilized not just as a runner but as a pass (catcher). (I'm) just a bigger running back, ready to take the pounding in the NFL and ready to take the load for the Cardinals."

While Johnson may originally only be needed in a specialized role, the Cardinals were drawn to his versatility. Arians compared him to Matt Forte coming out of college – "maybe a little faster," Arians said – and was clear in that he sees Johnson as a potential three-down running back.

"I was holding my breath that he was going to make it down," Arians said.

While Johnson played at a small school, he excelled at the Senior Bowl and then performed well at the NFL Scouting combine. Northern Iowa mostly played against fellow lower-level programs, but Johnson had 203 receiving yards and a touchdown in the season opener against Iowa last season, and in 2013 had 199 rushing yards and four touchdowns against Iowa State.

"When it was big-time, he stepped up big time," Arians said.

Johnson returned kicks in college and will be a candidate to do so with the Cardinals. The addition of Johnson won't change Ellington's duties moving forward.

"Andre will just continue his same role," Arians said. "We'll keep him healthy and let him continue to develop as a player. The nice thing David can do, he can do everything Andre does so you don't have to change if there was an injury."

KEIM TRADES DOWN AGAIN

For the third straight year, General Manager Steve Keim traded down in the draft, giving up the No. 55 selection to the Ravens

for their second- and fifth-rounders (No. 58 and No. 158 overal). He selected Missouri outside linebacker Markus Golden at 58 and will have six picks in the final four rounds on Saturday. Keim said it was a "calculated risk" making the move and hoped Golden was still on the board.

"I had an idea who Baltimore wanted," Keim said. "At the end of the day, you have to have enough players on your board you still like. The great part of it is to be able to acquire another pick in the draft and to be able to still get the player you wanted."

By adding Baltimore's fifth-rounder, the Cardinals are scheduled to pick consecutively at 158 and 159 in the fifth round. They traded down in the first round in 2014, nabbing safety Deone Bucannon and wide receiver John Brown for the pick which allowed the Saints Brandin Cooks. They added Ellington with an extra sixth-round selection from the Giants in 2013.

"I'm not the smartest guy," Keim said. "I just sort of realized the more lottery tickets you have, the more chances you have to hit."

ROLLER COASTER OF EMOTIONS

Keim admitted there was a player he really liked who went off the board before the Cardinals picked on Friday. He said it's part of the process over these three days, and that it's important to move on.

"(Arians) saw me today get probably a little more animated than I usually am because we missed out on somebody I was excited about," Keim said. "Conversely, the same for him. There are a lot of ebbs and flows to the draft. We've just got to trust in each other and know we're going to do the right thing."

The longer the draft goes, the rarer it is Keim's favorite players get snapped up because team draft grades begin to diverge. He and Arians shared a smile when talking about the day's events, clearly surprised at some of the selections that were made.

"Generally when you talk about your first 20 players the way they're stacked, there are a lot of similarities to other teams' boards," Keim said.  "When you start getting to about 40, to about 65, it starts going haywire. Which is great, because it leaves a lot of good players that we like up there."