OPEN CAMP: July 30, Davie, Florida.

LAST YEAR: Dolphins finished at or near .500 for third consecutive year under coach Joe Philbin, extending long playoff drought. Aging defense ranked 20th in points allowed, compared with seventh and 11th in first two seasons under Philbin; in final four games Miami gave up 28, 41, 35 and 37 points. Most encouraging development was improvement of third-year quarterback Ryan Tannehill, who set franchise record for completions and became Miami’s first 4,000-yard passer since Dan Marino.

IMPORTANT ADDITIONS: DTs Ndamukong Suh, Jordan Phillips and C.J. Mosley; WRs DeVante Parker, Greg Jennings and Kenny Stills; TE Jordan Cameron;, CB Zack Bowman; G-T Jeff Linkenbach; C J.D. Walton; Gs Jamil Douglas and G Jacques McClendon; DB Brice McCain; LB Spencer Paysinger.

IMPORTANT LOSSES: WRs Mike Wallace, Brandon Gibson and Brian Hartline; TE Charles Clay; DL Jared Odrick; DT Randy Starks; DE Dion Jordan; LBs Dannell Ellerbe, Jason Trusnik and Philip Wheeler; RBs Knowshon Moreno and Daniel Thomas; Gs Shelley Smith and Daryn Colledge; C Samson Satele; CB Cortland Finnegan; S Jimmy Wilson.

CAMP NEEDS: Philbin must sort out revamped receiving corps, secondary and offensive line desperately in need of upgrade. In his first three seasons, Tannehill has been sacked NFL-high 139 times. Team remains thin at guard, and it’s unclear whether LT Braden Albert will return from knee injury in time for opener.

EXPECTATIONS: This is Dolphins’ 50th season, and past few have been disappointing. Optimism is highest in four years under Philbin, whose job is on the line. New receivers are expected to be better match for Tannehill’s skills, and with 1,000-yard rusher Lamar Miller returning, offense could be formidable. Suh should make defense better, although there are issues with linebackers and secondary. Even if Dolphins start strong, they’ll need to shake habit of late-season collapses to reach playoffs for first time since 2008, and perhaps even win postseason game for first time since 2000.