The six-year contract could be worth up to $62 million, just over $18 million of it guaranteed.
Brown was en route to Phoenix on Thursday night from his home in Virginia. He is to undergo a physical exam Friday before signing his contract and joining the Cardinals at training camp on the Northern Arizona University campus in Flagstaff.
"We were a bit frustrated by the amount of time it took and didn't think it had to take this long," Arizona general manager Rod Graves said. "...The proposal that we agreed upon today was not far from where we've been the last week or so."
The 6-foot-5, 323-pound offensive tackle out of Penn State was the No. 5 overall draft pick and has missed the Cardinals' first five days of practices.
The players immediately ahead of and behind Brown already had reached deals.
Defensive end Gaines Adams, the No. 4 pick, agreed to a six-year deal with Tampa Bay reportedly worth up to $46 million, with $18.6 million guaranteed. Defensive back LaRon Landry, the No. 6 pick who also is represented by Segal, agreed to a five-year, $41.5 million contract with Washington, with about $17.5 million guaranteed.
Brown has played mostly at left tackle, but that spot is held by free agent acquisition Mike Gandy. Oliver Ross has worked with the first team at right tackle so far in camp. Ross played for Whisenhunt when the coach was offensive coordinator at Pittsburgh, but lost his starting job with Arizona during last season.
Brown was the second offensive lineman chosen in the draft. Cleveland selected tackle Joe Thomas at No. 3. Thomas has signed a six-year deal reportedly worth $42.5 million, with $23 million guaranteed.
Brown, a third-team Associated Press All-American this year, earned two degrees at Penn State - in labor and industrial relations in 2005 and psychology in 2006.