Now that training camps are underway, team owners and fantasy football fans alike are holding their collective breath, praying to reach the regular season with their rosters intact.

Chances are they won't.

Three playmaking linebackers didn't even make it through the off-season healthy: Dallas' Sean Lee, Buffalo's Kiko Alonso and Atlanta's Sean Weatherspoon, all hurt in seemingly tame circumstances.

August inevitably will be filled with more cringes and crutches, even though the NFL has tried to make the game safer in recent years. The league has placed limits on padded practices and implemented more rules changes to protect players on both sides of the ball.

"Despite all the advances in sports medicine, nutrition and training, we just can't prevent all injuries," said Dr. Ed Laskowski, co-director of the Mayo Clinic Sports Medicine Center in Rochester, Minnesota. "What we can do is protect them as much as possible through training and technique."

That involves adaptive, specialized, neuromuscular programs for players at different positions. A cornerback, for instance, has to be able to backpedal, run sideways and twist and turn on the fly in ways linemen don't. So, there are different exercises they must do to maintain flexibility and stability in their joints, especially if they're coming off an injury.

"You don't train all football players the same," Laskowski said. "A tailback's going to be widely different than a lineman. A lineman is different than a wide receiver and very different than a corner and a safety. So, we want to train them to do their jobs as much as possible."

Teams have changed the way they have players train and rehab from injuries in recent years.

Weight rooms are no longer a bunch of bench presses and barbells where brute force is celebrated. They have become state-of-the-art complexes with cutting edge technology where dynamic movement and plyometric programs help keep players out of the training room.

Some strength and conditioning coaches such as Denver's Luke Richesson apply modern workout techniques like those used in mixed martial arts in their specialized programs.

Still, guys are going to get hurt.

"Really, regardless of what time of the year, as a head coach and an organization, you hold your breath," said Broncos coach John Fox, who stood on the sideline at the Super Bowl alongside five defensive starters, including Von Miller, in street clothes. "Football is combative and injuries are part of the game, whether it's the off-season, training camp, regular season or even in the playoffs."

Or working out back home, as Alonzo was in Oregon last month when he tore an anterior cruciate ligament.

Held out of organized team activities to continue his recovery from a foot injury, Weatherspoon was running under the supervision of the team's medical staff when he tore an Achilles tendon last month.

That sent the Falcons scrambling like the Bills and Cowboys to redo their defensive blueprint.

Lee tore his left ACL in May when his leg slid out from under him during a non-contract drill and rookie guard Zack Martin rolled over him.

Relatively tame to begin with, OTAs across the NFL were decidedly more docile after Lee's 2014 season ended on the first day of the Cowboys' off-season practices. His injury left the Cowboys without their locker room leader just four months after franchise sacks leader DeMarcus Ware was waived.

Ware gathered with his new teammates the next morning in suburban Denver, Lee's injury dominating the meeting as the Broncos prepared to begin their own non-padded practices.

"First of all, the players, we're really concerned ... really thinking about our health and not trying to go as hard, not like you have pads on," Ware said. He noted there was a fine balance between "just taking care of each other but being able to get your mental reps in and still being able to be physical (and) having the right technique."

Now that training camps have started, practices are a lot more physical.

In 11-on-11 drills, there's some 4,500 pounds of bodies banging around, with linemen engaging each other and speedy athletes darting every which way. Officials are blowing whistles and coaches are critiquing every minute of it as they try to figure which of these 90 players will survive the end-of-August cuts to 53.

The intensity ratchets up, careers are on the line and injuries are bound to happen.

"You try to do everything you can," Fox said. "We talked about when you're practicing against each other, being smart, trying not to finish. You get four practice games to work on your finishing against opponents. So it's something you try to avoid, but no matter how hard you try, sometimes it just happens."