FORT MYERS, Fla. -- For those who see it, it's a captivating spectacle. For Jackie Bradley Jr., it's nothing more than a routine.

The Red Sox' likely center fielder-of-the-future puts on an unexpected show during batting practice. While most fellow players cluster into small groups and engage in casual chatter with teammates, grabbing the occasional flyball that happens to fall into their gloves, Bradley stands alone in center field. His focus on the hitter in the cage for round after round of batting practice is encompassing. For him, it is as if the outfield grass is a sacred expanse that requires defense against any encroaching baseballs.

And so, even in a situation such as batting practice where there is no competitive consequence, when baseballs fly towards the gaps, Bradley sprints across the outfield to chase down anything he can. This form of "power shagging" -- an activity typically limited to otherwise sedentary pitchers who use it for conditioning purposes (Mariano Rivera comes to mind) -- is a solitary undertaking in which he is joined by none, and it may help to explain why he has few defensive peers among minor league prospects.

Catcher Dan Butler, who played with Bradley in Portland last year, recalls the shock of seeing what Bradley did during one round after another of batting practice.

"First day he came up, it was like, 'Easy, buddy. It's July!' But he's out there and he runs down everything. He's in full cleats, running around. It's almost game-like," said Butler. "I've never seen anything like it."

Few have. Bradley, who will turn 23 in April, brings some of the same enthusiasm, pride and flair to his position that compels onlookers to pay attention to everything that Jose Iglesias does at shortstop. A few rounds of batting practice make that much apparent.

A ball is hit to the gap in left-center. Bradley sprints to a spot and stops as the ball nestles into his glove. Another ball is hit to left-center. Sprint, two-step backpedal, catch. A grounder shoots through the infield to the right of second base and towards center. Bradley runs to his left, jumps over the ball and grabs it with his glove between his legs; in what seems like one movement, he fields the ball, pirouettes and tosses it back to the infield. Another ball is lofted towards the edge of the warning track; Bradley jogs and, with his back to the infield, makes a graceful over-the-shoulder basket catch.

If he wanted to, Bradley could have camped out under the final fly ball. Was this an act of showboating? Hardly.

While those who watch Bradley and the outfielder himself note that his outstanding defense reflects incredible instincts, it's far more than that. Bradley spends batting practice adding to a two databases that give him a mature sense of where a ball will conclude its flight. The first incorporates weather, trajectory, spin, field conditions and batter strength; the second involves the precise movements -- stride, angle, glove position -- that permit him to get to such a tremendous volume of balls hit between left-center and right-center.

And so, when Bradley amplifies the degree of difficulty in his power shagging, it is not eyewash.

"Sometimes, instead of getting around [the ball], I try to put myself in a difficult situation to see if I can re-enact a play," said Bradley. "You never know -- the spin, the wind, if you slip. I actually slow down in order to make a play more difficult sometimes.

"Every time I'm out there, I'm trying to work on something, whether it's getting good reads, seeing how my legs feel or something like that. When I got to pro ball, they started calling it power shagging and I just went with it," he added. "The more times you do things, the more comfortable you get doing it. Everything is about repetition. I just continuously do it, seeing balls off the bat, you get a feel. Some days might be different -- the lighting, weather. I'm trying to get a feel for the field and how everything is playing that particular day."

That commitment has paid off in jaw-dropping fashion. Talent evaluators inside and outside the Red Sox organization believe that the 2011 supplemental first-round pick has a chance to be a Gold Glove center fielder, thanks to his incredible routes, a seemingly impeccable radar for the baseball and a powerful throwing arm. He will not be confused for a burner any time soon, but his direct path to the ball permits Bradley to move with an exceptional efficiency that can render his outfield neighbors irrelevant, as right fielder Bryce Brentz learned while playing right field in Portland.

"We would joke around with Brentz. Brentz was sitting camped underneath and here comes Jackie running across him. It's almost like he was giving Brentz a rest in right field that day," said Butler. "It was almost like you didn't have to worry about balls in the gap as much."

"[Brentz] doesn't mind," chuckled Bradley. "He likes it because I take all the balls and he doesn't have to move. He's like, 'Go ahead.' "

In contrast to Iglesias, Bradley also has an advanced hitting approach, exhibiting patience and the ability to spoil pitches and work deep counts while spraying line drives from foul pole to foul pole, reacting to wherever the ball is pitched. All of that suggests the potential to be a leadoff hitter in the big leagues, and makes him a bit of a different animal from Iglesias, whose plate approach is far more crude.

Still, as hard as Bradley has worked to forge a solid offensive approach -- in his first full professional season last year, Bradley hit .315 with a .430 OBP (thanks to 87 walks), .482 slugging mark and .911 OPS -- he lights up when discussing his glove.

"Hitting, of course it's exciting. Everyone loves to hit. But when you see that exciting play, not everyone gets to see that too often," said Bradley. "You'll see home runs more often than the great highlight basket catches, robbing home runs -- that stuff fires me up.

"It's always big to play defense. It helps out the team, the pitching staff loves you," he added. "When I first played in pro ball, I think I went to the fence to try to get a ball during a game. I think it was like my first few games in High-A. All the pitching staff just came up to me, shook my hand. I was like, 'I'm just playing my game.' They were just very appreciative that I really go hard, play as hard as I can and in the right way."

How good is Bradley's defense? Consider the following:

When Bradley played with High-A Salem in the first half of 2012, the team gave up 4.3 runs per nine innings. After his promotion, the club permitted 5.6 runs per game, an increase of roughly 30 percent.

Prior to Bradley's arrival, Double-A Portland gave up 4.9 runs per game. Once he joined the Sea Dogs, Portland yielded 4.2 runs per game, a decrease of roughly 14 percent.

Perhaps other factors explained those changes in the fortunes of the two clubs. Perhaps.

Still, there's little question that Bradley has the potential to be a game-changer in the middle of the field, and it is in no small part because of the time and repetitions he's invested in the undertaking.

There is a caveat. Because Bradley spends so much time playing in all-out fashion prior to games, there is a physical toll -- or, at least, there seemed to be in 2012, as Bradley acclimated to the length of a professional schedule that was far longer than the college seasons to which he'd been accustomed. His numbers, consequently, suffered down the stretch in Portland after his electrifying offensive performance in both High-A and at the outset of his time in Double-A.

"Maybe it played a little role in my fatiguing at the end -- I don't know. But it's what I've always done," said Bradley. "Maybe I'll take a certain amount of rounds of power shagging and let off on other rounds a little bit."

But he hasn't reached that point yet. And so, there on the back fields of spring training, a show is taking place, day after day -- a display that takes place mostly in obscurity now, but that has helped to put Bradley on the fast track for Fenway Park at a very early stage in his career.