The Cardinals are busy surveying the free agent landscape, hoping to add more key pieces to a core which has won 21 games over the past two seasons. Free agency begins on Tuesday, and we'll break down the team's needs at each position leading up to the signing period.

More free agent analysis: QB I RB I WR I TE I OL I ST I DL I LB I CB

Free agent primer: Safeties

Cap numbers of players under contract for 2015: Rashad Johnson ($2.2 million); Deone Bucannon ($1.8 million); Tyrann Mathieu ($855,937); Chris Clemons ($745,000); Tony Jefferson ($588,368); D.J. Campbell ($585,000)

Scheduled free agents: None

Need: Low

Analysis: The Cardinals have little need to venture into the free agent market at safety as Bucannon, Mathieu, Johnson and Jefferson are all set to return. Injuries kept Mathieu from being an impact player last season while Bucannon was used mostly at linebacker in passing situations, but they have the potential to form a potent combination at the position. Johnson is one of the steadiest players on the team, as he led the Cardinals in interceptions a year ago while playing nearly every snap, and should again be a major part of the defense. Jefferson made the team as an undrafted free agent two seasons ago and has turned into a key contributor. The four safeties have different skill-sets, which will allow new defensive coordinator James Bettcher to maximize their abilities depending on the situation.

Devin McCourty was the most prominent free agent safety on the board, but he has reportedly agreed on a return to the Patriots. The Broncos' Rahim Moore and Buffalo's Da'Norris Searcy are poised to hit the open market, but the Cardinals have more pressing needs elsewhere. Safety is one position which looks set heading into 2015.

Notable past free agent S signings by the Cardinals: Yeremiah Bell (2013); James Sanders (2012); Hamza Abdullah (2009); Dexter Jackson (2003); Matt Darby (1996); Andre Waters (1994); Mike Zordich (1989).