The Kansas City Chiefs have released Brandon Flowers.

Flowers was named to his first Pro Bowl this past season, but he had been absent from the Chiefs' offseason practices. Flowers was shifted to nickelback last season in obvious passing situations.

Marcus Cooper had replaced Flowers in the startling lineup in offseason practice.

Flowers struggled in the Chiefs' new defensive system, which called for him to often cover bigger and more physical receivers.

Colin Kaepernick credited Alex Smith's mentoring to him as he signed a $126 million new deal.

"I don't think I would be at this point so quickly if (Alex Smith) hadn't been such a great mentor to me and helped me along with things," Kaepernick said at a Wednesday news conference to announce the deal. "I'm very grateful for my teammates as well. I wouldn't be here without them."

Kaepernick acknowledged that he needs to improve his game still.

"I think right now, improving on getting through progressions, making the right reads and doing it every play is something that can take me to the next level as a player and take this offense to the next level," Kaepernick said in an interview that will air on "NFL Total Access" at 8 p.m. ET. "And that's something we're constantly working on and we get to do it against one of the best defenses in the league every day."