Upton wearing a different team's uniform will no doubt be jarring for some D-backs fans. Drafted by Arizona with the first overall pick in the 2005 First-Year Player Draft, Upton made it to the big leagues in 2007 and quickly became, in many ways, the face of the franchise.
In 2011, Upton finished fourth in the Most Valuable Player Award voting and helped lead the D-backs to the National League West title. With a contract through 2015, he seemed to be an Arizona fixture.
But 2012 did not go as planned for Upton or the D-backs.
Upton hurt his thumb sliding into second in the season-opening series against the Giants and the injury robbed him of his power. Meanwhile, the D-backs performed below expectations as a team.
As July rolled around, Upton's name began appearing in trade rumors just as they had in the fall of 2010 when Kevin Towers first took over as D-backs general manager.
Upton wound up finishing the season in Arizona, but after having his name tossed around in trade rumors for the second time, his agent Larry Reynolds told Towers that it might be in everybody's best interests if a trade got worked out in the offseason.
"For me, it was more it being publicized," Upton said of the rumors. "Obviously, the organization was moving in a different direction and that was their goal, to put a team on the field that they wanted on the field. I was OK with that, but at the end of the day, if it wasn't so publicized everything would have been fine."
Instead, rumors swirled throughout the offseason, and Upton had to answer questions from friends and family members about what might happen.
"I think more than anything, from the outside, people were anticipating something would happen," Upton said. "For me, as long as it went on, I had to try and block it out, which I did and whatever happened, happened."
In January, the D-backs agreed to a deal with the Mariners for a package that included some of Seattle's top prospects. The Mariners, however, were on Upton's limited no-trade list and he declined the trade.
Two weeks later, on Jan. 24, Upton was finally dealt to the Braves for Martin Prado and prospects.
"Being traded is a part of the game and you take it in stride," Upton said. "I've turned the page. I'm part of a new organization and it's still the same game on the field. I'm looking to the future and I'm enjoying things."
It's no surprise that Upton is having fun given the way the season has started. Though he has cooled a bit, Upton hit 12 home runs with 19 RBIs in April to capture the NL Player of the Month Award. Meanwhile, the Braves have gotten off to a quick start in the standings, entering Friday tied for the most wins in the National League.
"There's a lot of young, talented guys who only have one thing on their minds and that's winning," Upton said. "So it's been an easy clubhouse to be a part of and it's a lot of fun stepping on the field every day with them."
Some say the success that Upton is having this year is proof that he needed a change of scenery, or that he is extra motivated to perform to make the D-backs pay for trading him.
Upton says the difference is health. That thumb injury bothered him more last year than he let on. With the team battling to stay in the division race and his teammate Chris Young already out with an injury, Upton elected to play through the pain rather than go on the disabled list.
"I never got comfortable swinging the bat again after that first week when I hurt my thumb," Upton said. "I had to make certain adjustments, and it didn't work out as well as I wanted it to, but I went out and played as many games as I could and I was happy with that."
D-backs manager Kirk Gibson was asked about Upton's return during his pregame session with the media Thursday.
"I hear a lot of people say we didn't have a good relationship, but I disagree," Gibson said. "I enjoyed my time with him. He had a tough year last year and there were a lot of reasons for it. I understood his frustrations because I went through a lot of the same when I was a young player. I don't root against him, I want him to play well. But at the same time, we're going to try to beat him when he comes here. He knows that and he's going to try to get me, and I respect that."
While the trip back to Phoenix will no doubt open some old wounds, Upton is trying to focus on the positives like seeing some of his former teammates.
"That's the one thing that was constant when I was part of that team, was how great my teammates were," Upton said. "I'm looking forward to seeing those guys and competing against them. We love playing the game, and I know when I was in the clubhouse with those guys, we played together every night, and so to compete against them will be different, but I think it will be fun and a good atmosphere."