Justin Upton's name began surfacing in trade rumors before the All-Star break, when the Arizona Diamondbacks made it clear they would be open to offers for their 24-year-old tools-laden right fielder. The news updates sparked a frenzy of speculation, which subsided in late July when managing partner Ken Kendrick and team president Derrick Hall stepped in and squashed the chatter.

Life has now settled into the more comfortable rhythms of a pennant race, and Upton has gotten a second wind. He looks more relaxed and self-assured at the plate, and the Diamondbacks are pushing hard to stay close to the San Francisco Giants and Los Angeles Dodgers in the National League West race.

So where will the plot go from here? The Upton trade landscape could be more inviting in the offseason, when 29 other teams have a chance to take stock, assess their rosters and payrolls, and come up with a more attractive package of talent. Or maybe Arizona general manager Kevin Towers will decide to keep Upton, the Diamondbacks embrace him as their franchise face moving forward, and the events of this summer will go down as just a blip in a long and productive relationship.

The Diamondbacks previously caused a stir in November 2010, when they tossed out Upton's name as a trade candidate. Upton has now had to wrap his mind around the possibility of being uprooted twice in less than two years. How many times does a kid have to hear his name in trade rumors before he starts to take it personally?

"I can only control what I'm doing right now,'' Upton says. "When we get to the offseason, we'll cross that road. It's not hard to play for this organization because I owe it to the [other 24] guys in this clubhouse to show up and play every day. We'll deal with the other stuff when we get to it.''

If you sense a slight chill in the desert air, you're not alone. There's peace at Chase Field, but it feels like a tenuous peace.

Trying season

A year ago, the Diamondbacks would have had a hard time keeping a straight face -- much less verbally engaging -- if another team had inquired about Upton. He won a Silver Slugger Award, made his second All-Star team and finished fourth in NL Most Valuable Player balloting in 2011. Upton also has three years and $38.5 million left on a six-year deal that runs through 2015, so that means cost certainty moving forward.

But Upton hasn't been the MVP in his own clubhouse this season, much less a league MVP candidate. After hitting 31 homers last year, he has nine this season. His slugging percentage has dipped from .529 to .404, and he has an offensive Wins Above Replacement of 0.7 compared to 4.7 in 2011.

Upon isn't hitting the ball in the air as often or pulling it with much authority. According to ESPN Stats & Information, his ground ball rate is up (from 37 to 45 percent) and his fly ball rate is down (from 46 to 34 percent). He has also been strangely unassertive, taking called third strikes at an alarming rate.

What's the problem? Pick a theory. Upton hurt his thumb in April and got off to a slow start. Opponents are most likely pitching him more carefully after his monster season, and his mechanics have been out of whack at times. An AL scout said he thinks Upton looks bulkier this season, but Upton maintains that his winter workout regimen didn't change one iota. Finally, Upton wouldn't be human if he didn't feel a greater responsibility to carry the team now that he's become more established in his career.

"As much as people put expectations on me, my expectations for myself are even higher,'' Upton says. "So imagine what kind of pressure I put on myself. Maybe more than I need to.''

The groundswell of dissatisfaction in Phoenix gained steam in early June, when Kendrick appeared on a local radio show and vented about Upton and shortstop Stephen Drew. (Kendrick referred to Upton as an enigma.) Then the trade speculation ran rampant. Within baseball circles, the news of Upton's availability sparked the inevitable blitz of speculation: Is something going on with the kid that other teams don't know about?

Only the Diamondbacks know for sure what they hoped to achieve by bandying Upton's name about so freely. Did the Upton trade speculation create a buzz around the franchise? No doubt. But all that talk and no action left the D-backs with a dazed and confused young star on their hands.

“ As much as people put expectations on me, my expectations for myself are even higher. So imagine what kind of pressure I put on myself. Maybe more than I need to.

” -- Justin Upton

Some baseball observers speculate that Kendrick's comments were meant as a motivational tactic or a way to get Upton's attention. Team officials say privately that Kendrick is a "huge'' Upton supporter, but he was simply frustrated and puzzled by what he had seen between the lines this year. If his candor served as a wake-up call to Upton, so be it.

On July 4, a Chase Field crowd of 48,819 booed Upton in response to an 0-for-5 performance against San Diego. Upton compounded matters when he told reporters, "I don't care what the fans think of me.'' It was just a knee-jerk response to a case of hurt feelings. But Upton found that words can linger even when they're spoken in haste and frustration -- and there's no such thing as a mulligan on a postgame interview.

"Arizona has been good to me,'' he says in hindsight. "But it was disappointing to get booed the way I was. Obviously, I know I wasn't playing well. I understand where people were coming from because they want me to perform. But I want to win too. I want to perform too. I just think there are other ways to do it if you want to light a fire.''

Upton was stung more deeply by an Internet report citing anonymous executives who described him as "not a winning player'' -- a catch-all phrase that generally applies to players who are selfish, lack toughness or don't come through in the clutch. His agent, Larry Reynolds, quickly sprang to his client's defense, telling USA Today that it was "unfounded, negative rhetoric'' advanced by "gutless people'' who were afraid to attach their name to it. Upton, similarly, thinks the critique was out of bounds.

"People can comment on my production any day of the week and I'll own up to that,'' he says. "But it's a little bothersome when people challenge your character and they just don't know. Nobody knows how hard I work except for my teammates and coaches, or how hard I pull for teammates. Nobody knows that stuff, so they can't comment on that.''

Hall, the team president, recently told ESPN.com that he'll be "surprised'' if Upton is moved this winter. But he concedes that the Diamondbacks have a responsibility to be candid with Upton and let him know where things stand. With each new trade situation, the Diamondbacks have...