The 24-year-old made an instant impression on his debut last weekend as he picked up 87 yards from five catches in the first-half against the Houston Texans.
Brown tormented the defence as he appeared to be open on every play and was a constant threat in what was his first showing as an NFL player.
The third-round draft pick has received plenty of praise during preseason so far and Cardinals general manager Steve Keim has added to that by comparing the young star to former Cardinal, and now San Francisco 49ers wide receiver Anquan Boldin.
I haven't seen a rookie come in and do what he's done -- and it's early still -- since Anquan Boldin."
"This guy came through the first day, and being from Pittsburg State, has uncanny instincts, unbelievable understanding of route concepts, leverage, being in the right spot at the right time. On top of great ball skills, he has unusual speed and explosiveness," Keim said.
"He had five for 87 in the first half [against Houston], if you watch the film, he probably should have had seven or eight for about 200."
Cardinals quarterback Carson Palmer could have a dangerous wide receiving core at his disposal this season with Michael Floyd and John Brown accompanying the likely future Hall of Famer Larry Fitzgerald.
Brown will be one of many rookie wide receivers to watch this season with Sammy Watkins, Brandin Cooks, Kelvin Benjamin and Jordan Matthews also standout stars set for big campaign's.
The Cardinals will be dreaming of making the Super Bowl on home territory this year, but they will have to get out of the trickiest division in the NFL to reach the playoffs.
Arizona join St Louis, Seattle and San Francisco in the NFC West with the latter two both expected to go near to lifting the Vince Lombardi trophy at the end of the season.
The Cards got their preseason campaign off to a flying start as they beat Houston 32-0 in Arizona last Saturday, and they will hope to build on that performance when they meet Minnesota this weekend.
How far can the Cardinals go this season?