On Sept. 1, he threw out the potential game-tying run at home plate in Toronto for the final out of a 5-4 win over the Blue Jays. He hit three home runs in a Sept. 9 game against the Rangers, and Thursday he hit a walk-off three-run homer against the Red Sox.
The Rays have found a way to join the postseason party in three of the last four seasons. In each of those three seasons, Upton has excelled in September.
In 2008, Upton hit .291 with a home run and four RBIs in 16 games. That also happened to be the year that, despite having a bum left shoulder, he hit seven home runs in 16 playoff games to tie the American League record for a single postseason. The 2010 season saw Upton hit .261 with five home runs and 15 RBIs in September, and last season he hit .333 with five home runs and 20 RBIs for the month.
But this September has been special. He's hitting .268 with 10 home runs and 14 RBIs, and Tampa Bay still has nine games remaining on the schedule.
Upton maintains his juices aren't flowing any more in the last month of the season than they are during the rest of the campaign.
"I think it just so happens that it works out for me more than usual in the latter months of the season," Upton said. "But other than that, I can't really put a finger on it."
Rays manager Joe Maddon thinks otherwise, expressing his belief that Upton's late-season performances stem from a combination of factors.
"I think he likes being in these moments," Maddon said. "I think he likes that we're playing for something. I think competitively he kind of has this calm demeanor. But he's got this high-competitive fire burning within him. And then, beyond that, you've got this chance to go to the World Series again."
Given his talent and penchant for the big moment, Upton should be one of the more revered players on Tampa Bay's roster. Oddly enough, he has been a polarizing figure for the fans.
Upton's cool demeanor is a part of the equation. He can do so many things on the field with such grace and ease, that some associate that with not caring and not trying.
James Shields and Upton rank as the two longest-tenured Rays players, and Shields believes Upton's athleticism is his gift and his curse.
"It's really funny, because I've been watching him for 10 years now, and the first time I saw him run, it just didn't seem like he was even trying to run," Shields said. "And the next thing you know, you put a clock on him and he's running like 6.3 60s, and you're wondering how he does that, because it just didn't look like he was running that fast."
Upton conceded that being a target of some fans has been hard "at times," but he noted that he is "beyond that."
"At this point, they're going to think what they're going to think about me," Upton said. "I can't really control it. The guys in this clubhouse, they know what I'm about and how I play the game -- how I want to win. And that's the main thing.
"It's about playing smart and staying on the field. You can't help the team on the bench or on the DL. And I think that goes on around the league. The biggest thing is staying on the field and helping your team win."
Part of the fans' discord with Upton has been in relation to numerous cases of missing the cutoff man, throwing to the wrong base and getting picked off. But Maddon believes that most of that baggage can be seen only via a rearview mirror.
"His game has matured, meaning I've seen him throw to the right base and not the wrong base more consistently this year," Maddon said. "I've seen him choose the right places to run in and not the wrong places. Decision making on the bases themselves, I think he's made better decisions this year on the bases. I've seen this maturation of his game a little bit."
When asked about the past mistakes, Upton spoke in the quiet voice he often assumes during interviews.
"It's just learning, man -- the learning process, like knowing when to run," Upton said. "I know when to make people think I'm running so the guy in the box sees better pitches. I know what counts to run in. I know what the favorable pitchout counts are. I know guy's patterns, what he's going to do in certain counts and when it's best for me to steal bags.
"I think it's just a learning process. I used to just run because I could run and chances were I was going to be safe, and sometimes not the best situations to run. But I've kind of picked those situations out and picked my spots to run."
Upton's numbers paint a compelling portrait. By hitting his 100th career home run earlier this season, he became part of an elite group of players who had accrued 100 home runs and 200 stolen bases before turning 28. The others on the list include Barry Bonds, Rickey Henderson, Lloyd Moseby, Bobby Bonds, Eric Davis, Cesar Cedeno and Hanley Ramirez. Not bad company, and not a bad time to be heading into free agency.
Upton would like to remain with the Rays, who paid him $7 million to patrol center field this season.
"I'd like to, yeah," Upton said. "But you don't know what's going to happen. You don't know what they're going to do. It's not really my concern. [I'm going to] just try to finish the season strong, give ourselves the best chance to get into the playoffs, and when that time comes, we'll deal with it. But until then, man, I can't really worry about it. The thing's going to play itself out anyway."
Many Rays fans would love to see Upton return to the team. Others would not, and it's likely his detractors would attribute his late-season heroics to a salary drive. Maddon strongly disagreed.
"I know people are going to talk about him being a free agent," Maddon said. "But he's been this guy regardless of that moment coming up or not. I think he likes playing this time of year, and he likes to win a lot."