Rams defensive end Robert Quinn got the best of Brown for most of the afternoon. Quinn recorded three sacks as well as three quarterbacks hits.
Brown, a 2007 first round draftee, also got called for holding in the third quarter of the contest, a 27-24 victory for the Rams. It was the seven-year veteran's first regular season game since tearing his right triceps in a preseason contest against Oakland in August 2012.
Cardinals general manager Steve Keim told Arizona Sports 620's Doug and Wolf Monday that he was disappointed with Brown's performance in St. Louis.
"There's no way to sugar coat it," Keim said. "I take it personal, because it wasn't good enough. And I think it starts with me. It comes down to making sure that (offensive coordinator) Harold Goodwin and (offensive line coach) Larry Zierlein continue to work with him."
Keim said he saw some "technical issues" with how Brown played, including not moving his feet and how he used his hands to block.
"There are so many options," Keim said of the Cardinals offensive line depth. "We'll continue to look at those moving forward, and hopefully that'll improve this weekend against Detroit."
The general manager said the offensive line as a whole made several mistakes against the Rams defense.
"Looking back at the film, there were some issues where we just had one man to beat (in the running game) or there was one guy that was unblocked," Keim said.
On the brighter side, Keim said he was impressed by the play of starting guard Paul Fanaika. The former Arizona State Sun Devil was cut by the Seattle Seahawks in training camp last year and didn't play in the 2012 regular season. Although Keim identified a couple of quarterback pressures Fanaika gave up on Sunday, he said the right guard helped in the run game and played well overall.