Vikings cornerback Captain Munnerlyn wouldn't stop tweeting about his offseason workouts on Twitter over the last few months. It was clearly on his mind to improve physically after a down season in his first year with the Vikings.

Munnerlyn said he started his workout program right before the Super Bowl, earlier than when he'd normally begin to train. He felt he lost a step last year and wasn't in the best shape physically.

"I didn't play my best football," Munnerlyn said. "I pulled my hamstring early, started on the [Physically Unable to Perform] list. I just wasn't myself. I've gone back to the drawing board, and I'm excited again. I'm ready to play."

He said he's dropped 10-12 pounds and regained his speed. He revamped his diet, calling it the "LeBron James Diet" where he cut out red meat another other food items he enjoyed eating.

Munnerlyn, a seventh-round pick out of South Carolina in 2009, inked a three-year deal worth just over $11 million with the Vikings last offseason. He felt the increase in salary changed him mentally last offseason.

"I've joked with the guys about last year saying, 'I got a little new money last year and kind of got new to me,'" Munnerlyn said. "…It was a little different. I wasn't used to that. I wasn't use to it. But now I'm back to the drawing board, back to my roots."

Munnerlyn said he's out to prove he can once again be used as an outside cornerback and a nickel back. Among his doubters include Vikings head coach Mike Zimmer, who said at the Senior Bowl in January that Munnerlyn played out of position last season. Listed at 5-9 and 195 pounds, Munnerlyn has been knocked as just a nickel cornerback throughout his career mainly due to his size.

"I just don't see myself as a nickel back," Munnerlyn said. "That's just me. I see myself as an every-down corner. I want to be on the field every single down. But if the process work out and I'm just a nickel, I'm going to be the best nickel I can be. I'm going to be the best nickel in the NFL, that's how I look at it."