KANSAS CITY, Mo. -- The Kansas City Chiefs already have made plenty of bold moves this off-season.
They made another one on Thursday.
The Chiefs agreed to terms with cornerback Sean Smith on a three-year deal, helping to shore up their secondary opposite cornerback Brandon Flowers. The move also gave the Chiefs the type of lockdown defender they needed to deal with a bevy of talented wide receivers in the AFC West.
Smith was widely considered among the best cornerbacks available in free agency.
He's spent his entire career with the Miami Dolphins, starting every game each of the past two years, and has 177 tackles and five interceptions in his four-year career.
The move was made possible in part because the Chiefs cleared salary cap space Thursday by releasing Matt Cassel. The quarterback had two years left on his six-year, $63 million contract.
"There are still a few holes left. There's no doubt about it," new Chiefs general manager John Dorsey said Wednesday, when asked to assess his roster. "It's how you go and attack that. But at the end of the day, players we acquire will be able to fill all the holes we need."
The Chiefs had two of the best cornerbacks in the AFC two years ago in Flowers and Brandon Carr, but they allowed Carr to slip away in free agency prior to last season.
They signed Stanford Routt as his replacement, but he never quite fit in and was released midway through the year. Kansas City played the rest of the way with Javier Arenas, an undersized defensive back better suited to the nickel, and second-year pro Jalil Brown as the starters.
Kansas City added depth earlier in the week by signing a three-year deal with cornerback Dunta Robinson, who has spent the past nine seasons with Houston and Atlanta, but evidently was still in the market for a cornerback who is just coming into his prime.
The Chiefs found it in Smith, a former second-round draft pick out of Utah.
He started every game as a rookie, but ran into trouble in 2010 -- he was benched at one point for violating team rules, and lost his starting job to Jason Allen. Smith admitted that he wasn't taking his job seriously, rededicated himself and became a standout in the Dolphins secondary.
He made a career-high 59 tackles and two picks last season.
The move for Smith came one day after the AFC West-rival Denver Broncos agreed to terms with wide receiver Wes Walker on a two-year deal to provide Peyton Manning with another pass-catching option alongside Demaryius Thomas and Eric Decker.
The Chiefs and Broncos have been two of the biggest movers in free agency, with the Chiefs trying to rebuild under Dorsey and new coach Andy Reid after finishing 2-14 last season.
Already, they've revamped their offence by trading for quarterback Alex Smith and signing wide receiver Donnie Avery, tight end Anthony Fasano and backup quarterback Alex Smith.
They've also added former Vikings safety Husain Abdullah and former Jets defensive tackle Mike DeVito to a defence that landed four players in the Pro Bowl last season.
"If you take one common denominator with the free agents brought in so far, there's a certain grit and toughness about them," Reid said this week. "I welcome that to our football team. I think our locker room will welcome that."