First-round draft pick D.J. Humphries (right) shakes the hand of team president Michael Bidwill after Humphries signed his first NFL contract Monday.

The transition from college player to pro is ongoing for D.J. Humphries.

Yes, he was a first-round draft pick, a player who was assumed would battle incumbent right tackle Bobby Massie immediately for the starting job. But coach Bruce Arians has said a couple of times Humphries needs to mature as he simply tries to move up the depth chart, and Humphries acknowledged Monday he can't disagree.

"Like (Arians) said, it's an adjustment every young player has to go through," Humphries said after signing his first NFL contract, a four-year deal with a fifth-year team option. "I feel like I am taking steps in the right way. I don't feel I am taking steps back. I am taking steps forward, even if they are baby steps."

Humphries' contract is worth $8.9 million, with a signing bonus of $4.7 million. He was the last of the Cardinals' seven draft picks

to sign. Last year's first-round pick, safety Deone Bucannon, signed June 5. Where once the first-round pick signing was a summer-long process that often veered into training camp, the collective bargaining agreement reached in 2011 – and the "slotted" rookie salaries that came with it – eliminated the contract battles that once took place.

It allows Humphries to focus upon on-field battles. His new contract exceeds the money of the former fourth-rounder Massie, but as Arians has shown, that doesn't mean much. All the Cardinals' draftees are still working on the second practice field, with Arians noting Monday that third-round running back David Johnson is "not in the picture yet" in terms of potential playing time.

The same goes for Humphries.

"You'd like to see steady improvement in practice habits, work habits, weight room habits, and he's doing that," Arians said of the tackle.

"He's only 20 years old, 21 years old," Arians added. "He's a college kid still and this is a professional league. He's figuring it out fast, though."

Humphries said he's simply trying to get better daily, and while offensive line coaches Harold Goodwin and Larry Zierlein have blistered him from time to time after mistakes, no one is harder on Humphries than Humphries.

When Humphries arrived, he said he'd work but added he had never come off the bench and wasn't planning on it now. Early reality on the field has hit him, but he said it wouldn't change his outlook.

"That wouldn't be me," Humphries said. "If I tried to be, 'Aw, I'm just trying to dress' that wouldn't be the person I am. I'm trying to be the best. That's how I roll. … That's the way my dad raised me. If you're going to do something you're going to do it to the best of your ability. If it doesn't work out for me then, I'm confident I'll have given it my best shot."

His first-round status – now cemented with a contract – provides reason for confidence as well, whether or not 2015 is when he ascends the depth chart.

"I've been practicing that signature for, about, 15 years waiting for this moment," Humphries said.

RUCKER GETS AN EXTENSION

The Cardinals also agreed to a one-year extension with defensive end Frostee Rucker Monday. Rucker contract now runs through 2017.