Peterson signed a five-year, $70 million extension with the Cardinals over the offseason after being named to the Pro Bowl each of the last three seasons. Through five games this season, Peterson has given up four touchdowns and has been called for five penalties.
"I do believe I'm not playing to the best of my ability right now, but that's going to change," Peterson said.
On Monday, Arizona head coach Bruce Arians said the cornerback's performance against Washington last Sunday, which saw him give up two touchdowns, was not up to par.
"Not good for him," Arians said of the game. "Got beat on an inside route where he was supposed to have inside technique. Can't happen. It was not his best game."
Peterson said he knows he has added scrutiny now because of the contract he signed, which makes him the highest paid cornerback in the NFL.
"It comes with the territory," he said. "Is that something I might shy away from? Not at all. Is that something I'm scared of? Am I worried about the concerns or the criticism I'm getting so far this season? Not at all because we have 11 more games to go.
The 24-year-old has 14 tackles and one pass defended so far in 2014. Last season, Peterson had 42 tackles, three interceptions, two fumble recoveries and 13 passes defended.
The Cardinals (4-1) play the the Raiders (0-5) in Oakland on Sunday.
- Molly Geary