Smith has 42 regular-season sacks through his first three NFL seasons since being a first-round pick out of Missouri in 2011. He will turn 25 on Sept. 25.

San Francisco became all too familiar with the police blotter this offseason with Kaepernick, Smith, Culliver and others having run-ins with the law. In his 10-minute talk with his team following a spring practice, Harbaugh had some pointed words.

"Beware with whom you associate," he said. "Very important to know your surroundings. Friend or foe. There always seems to be a foe present. Get into a good football position and be ready for anything that's coming at you. Be able to see around corners, see under doors, anticipate. But mainly, surround yourself with good people."

Here is a snapshot of the 49ers roster as they head to camp:

QUARTERBACKS: Starter -- Colin Kaepernick. Backups -- Blaine Gabbert, McLeod Bethel-Thompson, Josh Johnson, Kory Faulkner.

RUNNING BACKS: Starter -- Frank Gore. Backups -- Kendall Hunter, Carlos Hyde, LaMichael James, Marcus Lattimore, Jewell Hampton, FB Bruce Miller, FB Trey Millard, FB Will Tukuafu.

TIGHT ENDS: Starter -- Vernon Davis. Backups -- Vance McDonald, Garrett Celek, Derek Carrier, Asante Cleveland, Kevin Greene.

WIDE RECEIVERS: Starters -- Anquan Boldin, Michael Crabtree. Backups -- Stevie Johnson, Quinton Patton, Brandon Lloyd, Bruce Ellington, Kassim Osgood, Jon Baldwin, Chuck Jacobs, David Reed, Devon Wylie.

OFFENSIVE LINEMEN: Starters -- LT Joe Staley, LG Mike Iupati, C Daniel Kilgore, RG Alex Boone, RT Anthony Davis. Backups -- T Jonathan Martin, G Adam Snyder, C Marcus Martin, G Joe Looney, G Ryan Seymour, G Brandon Thomas, G/C Dillon Farrell, G Fouimalo Fonoti, T Carter Bykowski.

DEFENSIVE LINEMEN: Starters -- RDT Justin Smith, NT Glenn Dorsey, LDT Ray McDonald. Backups -- NT Ian Williams, LDT Tony Jerod-Eddie, RDT Demarcus Dobbs, T Tank Carradine, NT Quinton Dial, NT Mike Purcell, DT Kaleb Ramsey, Lawrence Okoye.

LINEBACKERS: Starters -- OLB Aldon Smith, ILB Patrick Willis, ILB NaVorro Bowman, OLB Ahmad Brooks. Backups -- OLB Corey Lemonier, OLB Dan Skuta, ILB Chris Borland, ILB Michael Wilhoite, ILB Nick Moody, ILB Blake Costanzo, Shayne Skov, Chase Thomas, OLB Aaron Lynch.

DEFENSIVE BACKS: Starters -- FS Eric Reid, SS Antoine Bethea, CB Tramaine Brock, CB Chris Culliver. Backups -- S Jimmie Ward, CB Chris Cook, CB Dontae Johnson, CB Perrish Cox, CB Darryl Morris, CB Keith Reaser, CB Kenneth Acker, S Craig Dahl, S D.J. Campbell, S James McCray, S C.J. Spillman, S Bubba Ventrone.

SPECIAL TEAMS: K Phil Dawson, P Andy Lee, LS Kevin McDermott.