SURPRISE, Ariz. — The baseball soared out of a pop-up machine, and the chase was on. A 6-2, 205-pound man gifted with freakish ability and cursed with fragile stability sprinted into shallow center field. Lorenzo Cain called off the shortstop, snagged the ball and skidded onto the infield dirt.
"Take it easy on those legs, man," a teammate said as Cain loped back to the outfield.
The warning was lighthearted, but the consideration is far from cursory. In the proscribed formula that spawns a Royals playoff berth, Cain is a critical component. This franchise placed a premium on defense when building this team, a philosophy that flows down even to the type of free-agent starters they pursue.
Cain operates as the outfield fulcrum. His fielding is considered elite by both advanced metrics and more traditional analyses. He summers on highlight reels. Manager Ned Yost projects him as a future Gold Glover.
Which is why his shaky health vexes. Cain played a career-high 115 games in 2013, but still sat out because of various issues. The litany of his leg injuries stretches the imagination, a collection of ailments like knee sprains and groin strains, torn hamstrings and torn hip flexors.
"I've probably hurt everything in my legs," Cain said.
Together with Cain's input, the organization has crafted an elaborate, deliberate, daily routine designed to increase his flexibility and protect him for a full season. Yost praised Cain for arriving to camp "as flexible as he's ever been."
Yet, the balance is delicate. Cain's musculature, stature and aggressiveness on the diamond make him prone to strains during the season, team officials say.
Strength and conditioning coach Ryan Stoneberg compared Cain to a Lamborghini, a car capable of reaching tremendous speeds that also requires a commensurate level of maintenance.
"Someone his size, able to run with that speed, for him to do that day in and day out, at that intensity, everything has to be just right," Stoneberg said.
The unreliability of Cain carries implications in the team's roster construction. They will likely carry five outfielders, with Jarrod Dyson as Cain's backup, which means they could open the season without a reliable backup shortstop. In addition, Yost has floated the idea of using right fielder Nori Aoki in center. Aoki played there 18 times during two seasons in Milwaukee.
The organization would prefer Cain flourishes in center, and perhaps progresses as a hitter in the process. He has just 867 major-league plate appearances. After the 2012 season, when Cain played only 61 games, the team devised a strategy to reverse the trend. They stressed alterations to his nutrition and offseason workouts. He was eager to listen.
"You can only hurt so many things until eventually you've got to change something," Cain said.
By now, Cain embraces his routine. Each morning begins in similar fashion. He receives electronic stimulation for his legs, which improves blood flow and promotes muscle growth. Then he soaks in the hot tub. Sufficiently loosened up, he completes a cardio workout.
Next comes the part so critical to his proficiency. "A full-fledged stretching program," Cain said. "Where I stretch pretty much every part of my body."
Stoneberg targeted one specific area as the root of Cain's trouble. Cain harbors natural "imbalances" in his hip muscles, which lack natural flexibility, Stoneberg said. The tightness in Cain's hips creates tension in other muscle groups and leads to breakdowns.
"Sometimes the tiniest imbalance can cause huge repercussions," Stoneberg said.
So, Cain logs time on a foam roll, toiling at the sort of exercises he didn't require when he was in his early 20s. When the Royals acquired Cain in the winter of 2010, as part of the Zack Greinke deal, he was 24 and still so raw. He'll turn 28 in April. The time to deliver on his promise is now.
"I think he's getting closer and closer," Stoneberg said, "to being a guy who hopefully can go out and not just start a season, but finish a season."