Pittsburgh Steelers defensive end Brett Keisel drives an off-road dump truck up the driveway towards the team dormitories as he arrives for the start of camp.
Eli Manning
Julio Cortez/AP
New York Giants quarterback Eli Manning runs warm up drills.
Adrian Peterson
Charlie Neibergall/AP
Adrian Peterson made news at the opening of camps with his thoughts on HGH testing.
Barkevious Mingo
(AP Photo/Mark Duncan)
Cleveland Browns linebacker Barkevious Mingo waits for the snap during training camp drills in Berea, Ohio.
Cam Newton
(AP Photo/Chuck Burton)
Carolina Panthers quarterback Cam Newton gives a fist-bump to Max Kalinowski, 6, of Spartanburg, S.C., during camp in Spartanburg.
Richard Sherman
(AP Photo/Ted S. Warren)
Seattle Seahawks' Richard Sherman signs autographs, including copies of his photo on the cover of Sports Illustrated magazine, following a camp practice in Renton, Wash.
Percy Harvin
(AP Photo/Ted S. Warren)
Injured Seattle Seahawks wide receiver Percy Harvin watches as other receivers go through practice drills. Harvin will get a second opinion on his sore hip next week in New York, and Seattle coach Pete Carroll says all options remain for how the injury is handled.
Chris Johnson
(AP Photo/Mark Humphrey)
Tennessee Titans running back Chris Johnson (28) tries to put a ball into a waste can as running back Darius Reynaud (25) tries to block him out during a drill at camp in Nashville.
Robert Johnson, Delanie Walker
Mark Humphrey/AP
Tennessee Titans strong safety Robert Johnson, left, and tight end Delanie Walker, center, work out with sledgehammers under the watch of assistant athletic trainer Don Moseley. Both players are on the injured reserve roster.
The Bears and quarterback Jay Cutler get to play for a new coach this season, Marc Trestman.
Reggie Bush
Carlos Osorio/AP
The former USC star begins anew with his third NFL team, hoping to lead the Detroit Lions to the playoffs.
Trumaine McBride, Tyler Sash
(AP Photo/Julio Cortez)
New York Giants cornerback Trumaine McBride, left, and safety Tyler Sash cool off at camp in East Rutherford, N.J.
Maurice Jones-Drew
John Raoux/AP
Jacksonville running back Maurice Jones-Drew walks off the field with his two-year-old son, Madden.
Ryan Tannehill
Lynne Sladky/AP
Miami Dolphins quarterback Ryan Tannehill gives a high-five to a jumping Casey Rizzi, 7, of Davie, Fla., after practice.
Kansas City Chiefs
Orlin Wagner/AP
Kansas City Chiefs running backs work out during Chiefs training camp in St. Joseph, Mo.
Darrelle Revis
Mike Carlson/AP
The Bucs are expecting big things out of their major offseason acquisition, Darrelle Revis. MUST WATCH VIDEO: Super Bowl champion Amani Toomer and SNY/WFAN on-air personality Marc Malusis discuss Darrelle Revis' recent knee surgery and if he will we be the same as was before his injury.
Miami Dolphins
Gary Bogdon/SI
If the shoe fits, wear it.
Ryan Tannehill
Lynne Sladky/AP
Ryan Tannehill talks with his wife, Lauren, after a Dolphins practice.
Dolphins fans
Gary Bogdon/SI
Miami has its share of fanatics at camp this year.
Tim Tebow
Jim Rogash/Getty Images
In addition to his quarterback reps as camp opened, Tebow also caught passes and lined up with receivers and backs in other drills.
Tim Tebow
Jim Rogash/Getty Images
When asked where Tim Tebow might line up, Bill Belichick told reporters, "I think we'll use Tim where ever we feel like is best for the team. I know that's what he's committed to doing as well, whatever that is."
Aaron Dobson
Jim Rogash/Getty Images
Levelle Hawkins completes a passing drill during the first day of camp.
Philadelphia Eagles rookie DT Bennie Logan cools off during a training session. MUST WATCH VIDEO: Super Bowl champion Amani Toomer and SNY/WFAN on-air personality Marc Malusis discuss the quarterback competition in Philadelphia and why Matt Barkley will not come out on top.
Ifeanyi Momah
Matt Rourke/AP
Philadelphia Eagles wide receiver Ifeanyi Momah catches a tethered ball.
Mike Wallace
Lynne Sladky/AP
Miami Dolphins wide receiver Mike Wallace signs autographs for fans.
Patrick Mannelly
(AP Photo/Nam Y. Huh)
Chicago Bears long snapper Patrick Mannelly hikes the ball during training camp at Olivet Nazarene University in Bourbonnais, Ill.
Monte Kiffin, Bruce Carter
Gus Ruelas/AP
Dallas Cowboys linebacker Bruce Carter talks with Defensive Coordinator Monte Kiffin.
Robert Griffin III
Steve Helber/AP
Griffin III signs autographs for fans after a Redskins practice.
Robert Griffin III
Steve Helber/AP
Griffin III walks off the field with fan Michael Dabney, 7, of Richmond.
Desmond Trufant
John Bazemore/AP
Atlanta Falcons defensive back and first round draft pick Desmond Trufant arrives for training camp in Flowery Branch, Ga. Trufant signed his contract with the Falcons shortly before reporting to camp.
Kyle Long
Nam Y. Huh/AP
Chicago Bears rookie Kyle Long arrives for training camp in Bourbonnais, Ill.
Bruce Carter, Sean Lee
Gus Ruelas/AP
Dallas Cowboys linebackers Bruce Carter (left) and Sean Lee talk while they stretch during Cowboys training camp in Oxnard, Calif.
DeMarcus Ware
Gus Ruelas/AP
Dallas Cowbows linebacker DeMarcus Ware prepares to get past the offensive linemen as they run plays without pads.
Dez Bryant
Gus Ruelas/AP
Dallas Cowboys wide receiver Dez Bryant jogs back to the huddle after running a pass pattern.
Will Davis
Lynne Sladky/AP
Miami Dolphins cornerback Will Davis interacts with fans after practice at training camp in Davie, Fla.
Tony Romo
James D. Smith/Dallas Cowboys/SI
Tony Romo expects to have more input in playcalling this season.
Miami Dolphins
Gary Bogdon/SI
The Dolpins were among the first teams to begin camp this year.
Johnthan Banks
Mike Carlson/AP
Tampa Bay Buccaneers cornerback Johnthan Banks (right) covers wide receiver Chris Owusu during camp.
Elvis Dumervil
Patrick Semansky/AP
New Ravens linebacker Elvis Dumervil pauses before joining teammates for training camp at the team's practice facility in Owings Mills, Md.
Josh Freeman
Mike Carlson/AP
Tampa Bay quarterback Josh Freeman gets a play from offensive coordinator Mike Sullivan.
Brennan Williams, Bryan Braman
Pat Sullivan/AP
Houston Texans Brennan Williams (73) and Bryan Braman (50) square off during a drill.
Jermaine Gresham
(AP Photo/Al Behrman)
Cincinnati Bengals tight end Jermaine Gresham takes a drink while stretching at the close of practice in Cincinnati.