Jose Fernandez's fastball averaged 94.9 mph in 2013, the third best among Major League Baseball starting pitchers.

His fastball was scouted heavily during his recovery from Tommy John surgery. He flashed speeds of 95-97 mph out of the gate, which excited scouts and fans.

However, Stephania Bell writes that Fernandez's fastball velocity puts him at higher risk for injury.

"But that electric velocity is accompanied by increased stress across the elbow joint, a fact not lost on Dr. Neal ElAttrache, who repaired Fernandez's elbow. ElAttrache, a renowned orthopedic surgeon of the Kerlan-Jobe Clinic in Los Angeles and team physician for the Los Angeles Dodgers, has performed numerous TJ surgeries but sees young flamethrowers such as Fernandez as a higher risk subset due to the force they are capable of generating," Bell writes.

"That potential risk is precisely why ElAttrache insisted the progression of Fernandez be controlled both in terms of time and volume, although he was making excellent progress in rehab and never experienced a setback."

In 2014, about one-third of Tommy John surgeries were revisions.

"With the recent increase in not only ligament tears but re-tears [of the graft], the concern is trying to match the graft maturation to the stress imparted on it," ElAttrache said. "The harder he throws, the more mature you want the graft."