International scouting recently drew an NFL general manager to Melbourne, Australia, for a few days of rugby. During a lull in the action one evening, his eyes drifted to the sideline. The head coach was walking to the end of the bench, where a team employee sat holding a laptop computer. The two conferred for a moment before the coach returned to his post and ordered a series of player substitutions.

The next morning, the telephone rang in the Arizona offices of Catapult Sports, one of several Australian-based companies that compile live data on athletic exertion. The general manager was brimming with questions for Gary McCoy, the company's senior sports scientist.

"He wanted to know," McCoy said, "what the hell had just happened."

The general manager will remain anonymous because he did not give Catapult permission to reveal his identity. What he had witnessed, however, was the use of a widely accepted supplement to Australian sports training -- an approach that is beginning to gain traction in the United States.

The coach had viewed a live digital display of each player's exertion and conditioning levels as recorded by a GPS machine embedded in jerseys. The technology added precise data to a decision coaches otherwise make by feel. Who is truly gassed? Who should have the most remaining energy? Who is nearing a danger zone for wear-and-tear injuries?

Rugby coaches in Australia and nearly 400 other sports leagues around the world have incorporated such data into their programs, informing decisions like game rotations, playing time and practice schedules. The goals: maximizing performance and minimizing injuries.

The latter objective is of particular interest in the NFL, which absorbs thousands of missed starts per season and is at odds with its players' union over the impact of an expanded regular season. New NFL Players Association president Eric Winston, in fact, told USA Today last week that an 18-game season is "dead in the water" because of the presumed additional injuries it would cause.

But what if that assumption could be challenged? Could an emerging technology help reduce injuries in the NFL over time? If so, would an 18-game season be more palatable?

The NFL declined comment on a protocol that nearly half its teams have experimented with in recent years. Winston expressed doubt this week that any current or near-future technology could assuage the union's full array of concerns, and a second NFLPA source said it would be a "major leap" to make a positive connection between technology and a longer season.

But a number of NFL coaches acknowledged their growing understanding and use of the data available, and there might be no better example of its potential than the 2013 BCS national champion Florida State Seminoles. Last week, Seminoles coach Jimbo Fisher said his team's soft-tissue injuries, such as muscle pulls and tears, have dropped by 88 percent since it bought the technology two years ago.

"[It] has allowed us to take a lot of the guesswork out of how tired the team is, where your pulls, your tears [are coming from]," Fisher said. "We've been able to apply that and use it full time and gain that information. It's on my desk the first thing when I walk in every day. How we practice, the adjustments I make individually, all that, I live by that thing, and [it's] how we do things. ... I think it's been very critical to our development and our consistency at keeping guys on the field."

The landscape

Catapult counts 14 teams among its NFL clients, including the New York Giants, Dallas Cowboys, Philadelphia Eagles, Miami Dolphins, Atlanta Falcons, Jacksonville Jaguars, St. Louis Rams and Buffalo Bills. The Seattle Seahawks, meanwhile, consulted with GPSports Systems for similar purposes last season.

Via telephone interviews, McCoy and GPSports athletic performance specialist Rod Lindsell helped construct a framework for how the technology works and the ways it can apply to NFL teams.

Tracking devices measure player movement during training, practice and games, compiling data on running speed, the force of collisions, friction created by the playing surface and more. A total "load score" is calculated and compared to individually designed profiles based on the player's history, giving coaches raw data and context for how much wear the body has absorbed during a day, a week or longer.

"It's basically an athlete's dashboard," McCoy said. "These are elite, high-performance competitors. You wouldn't drive a Formula One car without a dashboard of its performance information. We look at players the same way."

Florida State coach Jimbo Fisher credits GPS-based technology with helping the Seminoles reduce soft-tissue injuries by 88 percent in the past two years. Stacy Revere/Getty Images

The idea, as Florida State's Fisher said, is to take the guesswork out of practice scheduling and player maintenance. NFL coaches often change workout routines based on their perception of the team's condition, but this technology offers objective information. (Consider it the difference between feeling the hood of a race car and measuring its engine temperature.)

A player's profile might suggest that a load score of more than, say, 500 for a given week would put him in danger of pulling a muscle or straining a calf. If he has already reached 490 by the end of Thursday's practice, the coach would be well advised to rest him Friday and find a slower pace the following week.

Jaguars coach Gus Bradley embraced the technology after taking over one of the NFL's most injury-plagued teams, in terms of players placed on injured reserve, in 2013.

"So we did the GPS, and we really tried to stay true to it," Bradley said. "If I got the information back from [strength and conditioning coordinator Tom Myslinski] that said, 'Hey, this guy has gotten so many yards in the last two days and it's above what he normally does,' then we taper it back for him. Instead of four out of four reps, he'll get two out of four reps, and we try to stay pretty strict with that."

According to Lindsell, training camp is one NFL tradition that seems ripe for analytic intervention. Even with the dissolution of two-a-days, the still-common schedule of five or six consecutive practices followed by a day off "seems horrible from a structure point of view," Lindsell said.

"We know from the data that high-intensity training for six straight days in any athletic endeavor creates muscle damage," Lindsell said. "As with anything, the body gets stronger by healing itself. It's no wonder you see so many guys with strains and pulls in these situations.

GPS tracking devices produce detailed reports that can be used to reduce the risk of injury. GPSports Systems

"Think if you were training in a gym, would you do your upper and lower body for six consecutive days? No. You would do upper body one day, lower body another and then maybe cardio. The data suggests taking these principles onto the training field. You would have to customize it to getting ready for a football season, but rearranging the physical emphasis on a daily basis definitely lowers the risk for these kinds of soft-tissue injuries."

During one summer with the Falcons, Lindsell recorded six consecutive days of high-intensity sprinting by a wide receiver. Data showed the receiver was nearing a load score associated with a high chance of a muscle tear. The recommendation was to pull back quickly and allow for recovery.

"It can be pretty obvious when you look at the data display," Lindsell said. "You look at it and say, this is a four-week injury waiting to happen, and really it is completely preventable."

Meanwhile, the Giants contacted Catapult for guidance in making the transition from their outdoor grass practice field to their indoor facility, which has artificial turf. According to McCoy, the technology measured a 15 percent increase in load for Giants players after the shift indoors.

Most coaches know intuitively that turf is harder on the body than grass and try to adjust. But, McCoy said, "when they become aware of the data, they know exactly how much to peel back while not giving up anything relative to performance. So instead of running a drill for 25 minutes, you schedule it for 18 minutes. Or there might be some drills that should be eliminated altogether and replaced by others that make more sense on a harder surface. It's a more precise awareness."

Will it catch on?

The NFL's equipment code doesn't allow for GPS use during games, but that could change. The bigger obstacle is winning over a set of particularly traditional coaches who prefer to trust their instincts on player management.

Fisher's public praise sent waves through the industry last week, and it's well known in America that football innovations tend to bubble up from the high school and college ranks.

"If you present a change in the way somebody does something, there has got to be a reason to change," McCoy said. "We've tried to show the history of what happened over, say, eight years of Australian rules football, where we've seen injury reduction by 35 or 45 percent. A lot of coaches are going to be very, very skeptical about technology, but when you can show them results, that's something that you would think would be of high value to a coaching staff."

The NFL doesn't allow the use of GPS devices such as this one in games, but many teams have started using them to monitor players' practice workloads. GPSports Systems

Bills coach Doug Marrone, for one, said he uses the data mostly to measure "explosive running." He added, "I'm trying to get a sense from a coaching standpoint how much running is being done during the week and where I have to rest somebody."

Bradley said it can be challenging to limit a player in practice when traditional coaching philosophy preaches the value of repetition.

"The coaches will say, 'Let's get all four of the reps,'" he said. "But I think that comes from me. [I] take the information and say, 'This is the direction we want to go.' Because it doesn't matter. They can practice all they want, but if they're not ready to go on Sunday, it doesn't help us."

A degree of culture change is necessary as well, according to Lindsell. In most professional sports leagues, the equivalent of the strength and conditioning coach has more authority than the NFL's version.

"The model in so many other leagues is to have an athletic performance director who has a real say in, for example, how much volume of work is taking place on a Tuesday or a Wednesday," Lindsell said. "They are the athletic specialists who can best understand, translate and implement the data that's available. Our experience in American football is that it's still controlled by the coaches and that the strength and conditioning guys are limited to what happens in the weight room. That's against our experience in terms of performance and injuries."

Impact on an 18-game season

The decision to incorporate data is traumatic enough for NFL traditionalists. Could it really affect the debate over an 18-game season?

McCoy cautions that, at this point, technology can't slow what sports scientists call ballistic injuries. There isn't much that can be done to soften the blow of a 300-pound defensive lineman landing on a quarterback. Broken bones and torn ligaments remain part of the game and would presumably elevate in prorated fashion if the NFL added two more games.

"No one can really influence that," McCoy said. "But the things that are preventable -- the hamstring pulls, the calf strains, a quarterback's sore shoulder, what we call soft-tissue injuries -- those can all be impacted by smart and accurate conditioning."