Ryan Mathews Signing Adds to Chip Kelly's Laundry List of High Risk, High Reward

As the Philadelphia Eagles continue to transform their roster in an attempt to rebuild Chip Kelly's way, it's become clear the franchise is gambling on its allegiance to sports science. 

One day after trading away two separate Pro Bowlers in exchange for two new starters who didn't play a single game as a result of injuries in 2014, and one day after signing a free-agent cornerback who missed 14 games due to injury last season, the Eagles have signed injury-prone running back Ryan Mathews, according to ESPN's Adam Schefter. 

The 2010 No. 12 overall pick could replace LeSean McCoy, who was officially traded to the Buffalo Bills Tuesday, but Mathews missed 10 games last year due to knee and ankle injuries and has developed a reputation for being brittle.

He's been limited throughout his career by elbow, ankle, foot, groin, knee, calf, clavicle and hamstring injuries, which is why he's been able to play in 14 games just twice and 16 games just once. 

Between Mathews, Tuesday acquisitions Kiko Alonso and Sam Bradford and Walter Thurmond, whose signing the Eagles confirmed Wednesday, the Eagles have brought in four players who played in a total of eight of a possible 64 games last season. 

Player	Games played	Injuries
RB Ryan Mathews	6	Knee, ankle
CB Walter Thurmond	2	Torn pectoral
QB Sam Bradford	0	Torn ACL
LB Kiko Alonso	0	Torn ACL

That's an easy way to get a discount, but it, of course, comes with a huge risk.

Barring another injury or a draft- or trade-related turn of events, Bradford will be the starting quarterback, but the St. Louis Rams' first overall pick from 2010 has torn his ACL twice in as many years and has missed 33 games in five NFL seasons. Bradford also underwent major shoulder surgery at Oklahoma in 2009 and dealt with ankle problems in 2011. 

Thurmond is expected to play a key role at corner, but the veteran missed most of 2011 and 2012 due to leg and ankle injuries, was suspended four games in 2013 and played only 67 snaps last year with the New York Giants before suffering a season-ending pectoral injury. He's played in just 22 games the last four seasons. 

Alonso has history with Kelly at Oregon and was the PFWA Defensive Rookie of the Year as a Buffalo Bills linebacker in 2013, but he missed the entire 2014 campaign due to a torn ACL. 

If the Eagles can somehow manage to keep all or most of those talented newbies on the field all or most of the time, they'll likely be laughing all the way back to the playoffs in 2015. And there is reason to believe this organization has a better ability to do so than most. 

The Eagles aren't immune to injuries—the offensive line was ravaged early last season and they've had to use four different starting quarterbacks the last two years—but Kelly has invested heavily in sports science, and it appears that has paid off. 

Kelly's methods are unorthodox, both on the practice field and in the dressing and training rooms. His players have personalized smoothies that aim to enhance their health and recover, and he stresses particular approaches to diet, exercise and sleep. 

“Coach Kelly does a good job of getting us to put a lot of work in during the week, but we also have our bodies ready for Sunday,” cornerback Bradley Fletcher said during Kelly's inaugural season, per CSN Philly's Geoff Mosher. “We don’t put ourselves in position where we’re going to feel like we don’t have anything left in the tank. I credit that to the sports science, just how Coach Kelly runs his football team.”

And that has spread throughout the organization. In 2013, Jenny Vrentas of The MMQB detailed some of the ways in which the training staff utilizes sports science and technology in order to keep players fresh and lower their odds of suffering injuries: 

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The array of technology creates a physiological dashboard for each player. Among the equipment: Catapult Sports’ OptimEye sensors, which Barwin was wearing; heart-rate monitors from Polar; an Omegawave system that measures an athlete’s readiness for training and competition; and weight-lifting technology from a company named EliteForm, with 3-D cameras that record not just how much an athlete is lifting but how quickly he is doing it. There is also the low-tech end: Players are asked to urinate in a cup before practice to check their hydration levels.

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In fact, as Vrentas points out, the team has its own "sports-science coordinator," a man by the name of Shaun Huls. Huls' former job: performance coach for the U.S. Naval Special Warfare Group 2. 

It appears the entire approach has worked like a charm. 

According to numbers provided by Rich Gosselin of the Dallas Morning News, the Eagles lost six starters to injured reserve in 2012, Andy Reid's final season. That was tied for the league high. They also ranked eighth with 63 starter games lost to injury. But in Kelly's first season, they lost only one starter to IR and had only 29 starters miss games due to injury, which ranked fourth-fewist in football. 

Football Outsiders has its own formula to quantity the impact injuries have on each team. In 2012, the Eagles ranked worse than the league median with an "adjusted games lost" total of 73.3. But in Kelly's first season, that dropped to 33.6, ranking second in football. That total grew to 48.6 in 2014 but still ranked fifth in the NFL.

And if you combine those two seasons, the Eagles have been the healthiest team in football during the Kelly era: 

Team	2013	2014	Combined
1. Eagles	32.2	48.6	80.8
2. Jets	43.0	41.5	84.5
3. Ravens	47.4	52.6	100.0
4. Bills	44.3	59.0	103.3
5. Browns	41.1	67.0	108.1

Not pictured: San Diego and New York, where Mathews and Thurmond come from, rank 31st and 32nd, respectively. 

So maybe there's reason to believe all four of these guys can turn it around from a durability standpoint. Most are good fits, especially Mathews, who will have plenty of opportunities to excel within a strong run-based offense, behind a strong offensive line and with former San Diego teammate Darren Sproles giving him breathers.

He did average a stellar 4.5 yards per carry when healthy last season, and he ran for a solid 1,255 yards in 16 games in 2013. He's 27, almost a full year older than McCoy, but that time off means he has a lot more tread on his tires than a man who is tied for the league lead with 1,566 touches since 2010. 

McCoy was probably steadier, though, and had missed just six games in six seasons. Foles was less of a gamble than Bradford is. Thurmond's a mystery. Alonso has yet to establish himself. All have a lot more to prove, physically, than the players they'll be replacing. 

But that's Chip Kelly, rolling the dice on his heavy philosophical and literal investments. Scary, I'm sure, but the Eagles haven't won a playoff game since 2008 or a championship since 1960. They haven't got a lot to lose. 

Brad Gagnon has covered the NFL for Bleacher Report since 2012.

Follow @Brad_Gagnon