After picking up a pair of offensive linemen and several defensive starters in free agency and the draft, the are adding even more reinforcements from a previous draft cla s.By all accounts, 2013 first-round guard and third Buster Posey Jersey -round defensive back have fully recovered from major leg injuries that sabotaged their sophomore campaigns.Mathieu played 13 games last season, albeit in a part-time role as the coaches eased him back into the rotation. The now believe the versatile playmaker is "" before a torn ACL ended his Defensive Rookie of the Year bid in 2013, per Mike Jurecki of Fox Sports 910 in Phoenix.Although his 2015 role isn't set in stone, the ' offseason moves suggest Mathieu will split his time between safety and slot corner just as he did as a rookie.A healthy Mathieu is one of the game's most instinctive playmakers, capable of adding an extra dimension to new coordinator James Bettcher's defense.Still favoring his surgically repaired left leg and , Cooper was until late in the year.General manager Steve Keim finally started seeing Cooper's return at the beginning of December.Jurecki notes that Cooper has been at right guard in recent workouts, which jibes with Keim's mid-February update."We have for him," Keim told KMVP in Phoenix. "He has got to stay healthy."Since the start of last offseason, Keim has added rock-solid left tackle , left guard , 2015 first-round right tackle and Cooper.If Cooper is ready to fulfill long-awaited expectations, the Arizona offensive line can complete its transition from league-worst in 2012 and 2013 to one of the most dominant in 2015.The latest Podcast and makes rookie predictions for the 2015 season. Find more content on .* Sam Selman Jersey