Patrick Peterson acknowledged on Thursday what seemed evident a week prior: he struggled to contain wide receiver Emmanuel Sanders, and that failure contributed to the Cardinals' 28-25 loss to the 49ers on a nationally televised stage.
It was a rare misstep for one of the NFL's top cornerbacks, and one Peterson took to heart.
"I'm in a position to get criticized each and every move," Peterson said. "Nothing goes unnoticed. I know when I play well, we have a great opportunity of winning the football game. My role is almost equivalent to the quarterback's. When the quarterback plays well, the offense is successful and they have a good opportunity to win.
"When I have an opportunity to take No. 1 receivers out of the game, I have to do it at a high level, because that gives us an opportunity win the ballgame. After the game I told the guys, 'This loss is on me.'"
According to Pro Football Focus, Peterson allowed six catches for 118 yards and a touchdown on seven targets, which computes to a perfect passer rating. It was the first time since 2014 he allowed more than 100 yards receiving in a game.
"I just didn't play well," Peterson said. "I was in position to make plays. I was just a little off."
While most of the damage was done by Sanders, Peterson was also beaten for a 21-yard touchdown by Dante Pettis in the third quarter. That one wasn't totally his fault, as Peterson explained that there was a miscommunication between he and cornerback Byron Murphy as to whom should run with Pettis.
However, defensive coordinator Vance Joseph thought Peterson should have pursued Pettis harder when the throw was in the air.
"Every play we play on defense, we want to be full speed," Joseph said. "We don't worry about mistakes, because it's a game of mistakes, but we want everyone to have max effort. That goes for every player, not just Patrick."
Peterson acknowledged that he gave up on the coverage too soon.
"Honestly, because he was so open, I thought the quarterback was literally going to throw it on a line drive," Peterson said. "Looking back on that play, I definitely thought I could have given more. I thought I was out of position, but that just goes to show you're never out of a play until you're out of it. That was a bonehead mistake by me."
Coach Kliff Kingsbury avoided criticizing Peterson this week, pointing out that his star cover man faced the tough physical challenge of playing three games in 11 days immediately upon his return from suspension.
"Everybody has to understand, he has been off the couch for three weeks, and then that was a short week on top of it," Kingsbury said. "A lot of the repetitions of full-speed stuff that he needs to get himself back into playing shape and condition and top-form, it wasn't there last week."
Peterson believes he will improve as he reaches peak physical form, but didn't cast blame on it for his subpar showing.
"The legs were a little sluggish, but that wasn't the issue," Peterson said.
There is widespread belief throughout the team that this was a blip, and that Peterson will rebound on Sunday against the Buccaneers.
"Every player has their days where they are not going to be 100 percent perfect," safety Budda Baker said. "For Pat, he's perfect a lot of the time. He made a couple mistakes. The thing is, you're not going to get that out of him consecutive times."
Mike Evans will aim to test that theory. The Tampa Bay star has 50 catches for 842 yards and seven touchdowns on the season, and quarterback Jameis Winston has tried Peterson often during this matchup in the past.
Peterson, 29, has regularly come out on the winning side against No. 1 receivers throughout his career, and is confident the loss to Sanders isn't the start of a downward trend.
"This where you're able to leave your name in stone, when you're able to get your opponent's best shot each and every week," Peterson said. "That's what the Cardinals drafted me for. I've been doing it for a very long time, and I don't plan on stopping any time soon."
It was clear that the performance against Sanders bothered Peterson, but he promises the failure will only be used as fuel.
"Life is all about defining moments, and moments like that can either make or break you," Peterson said. "At the end of the day, that's going to make me work even harder."
Images from practice at the Dignity Health Arizona Cardinals Training Center