FORT MYERS, Fla. -- At a time when the hot-button topic in Red Sox spring training is the question of whether or not Jackie Bradley Jr. should open the year in the big leagues, it's worth considering the case of Mike Trout.

In 2012, Trout took the baseball world by storm. Promoted to the big leagues in late-April after just 20 games in Triple-A -- during which he hit .403 with a .467 OBP and .623 slugging mark with Salt Lake City -- he was among the best players in the game from nearly the moment that he reached the majors, offering a staggering first chapter in the career of a player who appears to be a once-in-a-generation, five-tool talent.

Indeed, his performance en route to American League Rookie of the Year honors (and AL MVP runner-up status) was so breathtaking that voices around the game were left to wonder whether the Halos would have reached the playoffs had he opened the year in the big leagues. His team was 6-14 at the time of his call-up, and 83-59 once he was promoted, ultimately missing the playoffs by four games due to its slow start.

(Worth mentioning: Some have suggested that the Angels fumbled away their season in an effort to manage Trout's big league service time and to delay his free agency by a year. This suggestion represents an act of revisionist history on a couple of levels. First, the Angels had been sufficiently comfortable with the idea of starting Trout's service time clock to the point where he spent more than two months in the big leagues in 2011 -- making it almost impossible that the team would be able to keep him in the minors for long enough to delay his service time to the point of delaying his free agency. Secondly, and perhaps more significantly, Trout missed almost all of spring training last year while dealing with a virus that caused him to lose 20 pounds as well as a shoulder injury that left him unable to play the outfield; given that he'd struggled at the end of 2011 in the Arizona Fall League and that he hadn't been able to make a case for his big league-readiness in the spring of 2012, the Angels had no choice but to demote him.)

Typically, there are two lessons derived from Trout's 2012 season. First, even with limited minor league experience and less than a month in which he'd played Triple-A, the 20-year-old Trout was ready for the big leagues, much as former Arizona Fall League teammates Bryce Harper (at 19 years old) and Will Middlebrooks (at 23) were last season. Secondly, the terrible cost of not having the most talented players on the roster at the Troutless start of the year was highlighted. He ostensibly represents a cautionary tale to the notion of the Sox taking a cautious approach with Bradley, who has been a head-turner every time he's stepped onto the field this spring.

But the view of whether or not the Sox should start the year with Bradley on the big league roster typically focuses on Trout's 2012 time in the majors. What, though, of his first taste of the majors in 2011?

Trout, then still just 19, was dominating his second full season of pro ball. Through early July, he was hitting .324 with a .415 OBP, .534 slugging mark and .950 OPS with nine homers and 28 steals through 75 games. When Gary DiSarcina -- now the manager of the Red Sox' Triple-A affiliate in Pawtucket, but then a special assistant to the GM with the Angels -- watched Trout in Double-A for a couple of weeks, he saw a hitter who had quality plate appearances in 40 of 45 trips to the plate, who swung at one first pitch. For DiSarcina, Trout's on-field maturity and personality suggested that, when Peter Bourjos went down with a hamstring injury in July, he was the best candidate to fill in for the Angels outfielder, despite the fact that he'd never played above Double-A.

But Trout performed poorly when called up, hitting just .163/.213/.279/.492. He was sent back down to the minors by the end of July. The experience was an uneasy one, the transition from Double-A to the majors so extreme -- both on and off the field -- that it temporarily swallowed a player of surpassing talents.

"I do remember asking him about the first two weeks up there -- it was spinning on him pretty quick. He was not the same player I had seen. It was spinning on him and there was a lot of pressure," said DiSarcina. "He wasn't himself those first few weeks."

All along, the Angels planned to send Trout back down to the minors -- and indeed, to Double-A -- once Bourjos was healthy, and they did just that. He again excelled in Double-A for three weeks before getting called back up. But while his second call-up went vastly better than his first, he still proved unable to demonstrate the ability to dominate at the big league level, hitting .250/.318/.450/.768 in the last 26 games of the season.

There are a couple of takeaways from Trout's experience in 2011 that merit consideration when it comes to Bradley.

First, a player with a considerable track record of success can still struggle when pushed aggressively -- particularly if he goes from Double-A to the majors without benefit of experience at the highest level of the minors.

"Triple-A ain't Double-A. In Double-A, the No 1 starter is like a fourth or fifth starter at the next level. Those middle relievers aren't garbage," said DiSarcina. "I think there's some shock [going from Double-A to the majors]. I got called up from Double-A. I wasn't ready. You've got to have that learning curve, and it goes back to makeup. If your makeup is very strong, then that learning curve is much quicker."

In Trout's case, because of his makeup, there was value in his initial exposure to the big leagues and in the lessons gleaned from struggles. Even though he faced the first meaningful struggle of his career, he was someone who could benefit from that experience. There are top prospects who are shell-shocked by their initial failure, but the best players are often the ones who can take failure in stride -- something that the Angels believed was the case with Trout in 2011 (and, of course, in 2012), and that, by most accounts and impressions, the Sox seem to feel regarding Bradley.

"I remember talking to [Trout] about how he felt [in the majors in 2011], and he just felt a little overwhelmed. But it was probably the best thing for him was getting that out of the way," said DiSarcina. "Mike never failed in the minor leagues. He never failed in high school. He never failed anywhere. So when he did in the big leagues, on a grand scale ... that's where you have to look at the player internally, the people who signed him, the scouts. The Angels knew Mike very well, his makeup. We thought he would be fine and bounce back. Mike plays like a grown man in a high school kid's body. It's like a whiffle ball game in his backyard. His makeup is off the charts. At 19, 20 years old, that was probably the difference in calling him up."

DiSarcina understands the parallels between the situation faced by the Angels with a player like Trout and what the Sox now face with Bradley. Though he would be Bradley's manager if the outfielder gets assigned to Triple-A, however, DiSarcina still has yet to work closely enough with the 2011 supplemental first-round pick to know first-hand what makes him tick or how his playing abilities might translate at the game's highest levels.

What Trout's call-ups taught DiSarcina was that decisions such as whether or not to call up a are complex, and made more so by the nature of spring training. Veteran pitchers are working on specific aspects of their game -- fastball command, for instance, or the emphasis of a certain pitch -- rather than focusing on outs as the be-all, end-all. No one is employing scouting reports to try to attack the center fielder's weaknesses. Bradley is, in many instances, facing players who might not themselves be major league ready, or at least not representative of the major league elite. Statistics are distorted by small samples and ballpark/weather idiosyncrasies. All of those factors render even the gaudiest of statistics of limited value.

That's not to say that a player's spring performance is irrelevant. Still, an outstanding spring performance -- or, for that matter, an ability to dominate in Double-A -- is not necessarily a harbinger of immediate success. The Angels thought Trout gave them their best shot to win when he was called up during the 2011 season. He didn't. They thought he gave them the best chance to win when he got called up in 2012. He did.

As for Bradley? The jury remains out. To this point, team officials suggest, they haven't seen enough to say that he would be worthy of an everyday job in the big leagues to start the year (even at a time when David Ortiz is expected to open the year on the DL).

But the fact that the Red Sox officials who must render the judgment on the outfielder at least still appear willing to let Bradley's play make an argument for a season-opening start in the majors -- albeit with a preference, in a vacuum, that he be given the time to round out his minor league apprenticeship -- says plenty about the impression that Bradley is making.

"There's so many variables. There are so many parts to deciding whether to call a guy up," DiSarcina said of the timing of a call up. "[But] a player's going to tell you when he's ready to get called up through his performance."

...

Again, knowing that a player is ready for a call-up is different than knowing that he can succeed when he's called up. A few other cases that illuminate the uncertainty surrounding the decision that the Red Sox must make with Bradley:

DUSTIN PEDROIA

A case can be made that Pedroia was even more advanced than Bradley after one full professional year. At the least, it would be hard to say that Bradley is more advanced than was Pedroia following the 2005 season.

Pedroia had never struggled or failed at any level. He'd made it to Triple-A by the second half of 2005, his first full professional season. Though he started slowly in 2006 when assigned to Triple-A Pawtucket -- following an injury that effectively wiped out his first big league spring training camp -- he ended up hitting .305 with a .384 OBP in 111 games in Pawtucket. He seemed like a player who had completed his minor league development.

Yet even the future MVP proved unready for the challenge that awaited him in the big leagues. He hit .191 with a .258 OBP and .303 slugging mark in 98 plate appearances. A transition to the big leagues had to take place before Pedroia could emerge as a central contributor to a winning team.

JOSE IGLESIAS

It was less than a year ago -- last March 21, to be precise -- that former Red Sox manager Bobby Valentine offered this assessment of Jose Iglesias in spring training:

"I think he can hit and field at the major league level," said Valentine.

Just over five months later, Valentine was pinch-hitting for Iglesias in the middle of an at-bat, at a time when the shortstop had done little to demonstrate that his offensive approach was indeed big league ready. This spring, after an offseason of adding strength, Iglesias is once again trying to make his case, even as he prepares for the likelihood of a third straight year in Triple-A Pawtucket (provided that shortstop Stephen Drew's concussion symptoms subside in time for him to be ready to play on Opening Day). He represents a cautionary tale for the Red Sox about rushing a player who possesses a skill set that is only partially major league ready.

JACOBY ELLSBURY

In 2007, Ellsbury's skills were advanced to the point where the Sox -- confronted with Coco Crisp's shoulder injury that kept the center fielder out for a couple weeks of spring training -- asked internally whether Ellsbury would be ready for the big leagues at the start of that year if Crisp went down. Crisp returned, however, thus rendering the question moot, and Ellsbury started the 2007 campaign (his second full pro year) back in Double-A, the same level where he'd finished 2006.

He started the year in unbelievable fashion, hitting .452 and earning a promotion to Triple-A Pawtucket about a month into the year. Yet even with numbers in Double-A that year that were somewhat reminiscent of Bradley's in spring training this year, Ellsbury's performance in Triple-A was far more modest, as he hit .277 with a .352 OBP prior to getting promoted to the Red Sox at the end of June (an opportunity created by an injury to Crisp).

Even so, he proved a game-changing performer when called up by the Sox, hitting .353 with a .394 OBP and .509 slugging mark while also proving a game-changer on the bases. It is interesting to note that Ellsbury, who performed at arguably the highest level out of the gate of any Red Sox position player making his big league debut, did so after following a development path that was conservative relative to that of Pedroia or Iglesias.

And in that vein, it's worth noting that while the team has not ruled out completely the possibility of Bradley starting the year in the big leagues, nor, according to one major league source, has it ruled out the possibility of him starting the year back in Double-A -- a level at which he had just 271 plate appearances last year.

Still, that same source acknowledged that Bradley is more polished at this point in his career than was Ellsbury in spring training of 2007, given his mature plate approach and excellent strike zone recognition.