Then in November, he got an unexpected sign of St. Louis fans' dedication during the Chicago Cubs' World Series parade, when he says he noticed a surprising amount of Cardinals red on the streets of the Windy City.
And on Thursday, as he flew from his home in Las Vegas to St. Louis to have a physical -- the final hurdle before signing afive-year, $82.5 million contractwith the Cardinals, which he completed on Friday -- he got another reminder of how engaged the team's supporters are.
A flight attendant and a fan on the flight, after taking advantage of in-flight Wi-Fi, approached Fowler to find out whether the rumors were true. Fowler responded by trying to go back to sleep, but the next day he expounded on what, other than the finances, made playing in St. Louis so appealing.
"You get a taste of winning a World Series and you want to do that again," Fowler said at his introductory news conference. "You're excited and you want to get back and win the World Series. With the Cardinals, they're always in the hunt. That was a big part of my decision."
Fowler said Cubs president Theo Epstein called him shortly before Chicago acquired Jon Jay to inform Fowler the team would not be making him an offer to return.
The Cardinals had to extend beyond their comfort zone to sign Fowler, offering him a blanket no-trade clause, according to a source, to go with a contract that some in the industry view as market-altering. The deal will pay Fowler $16.5 million per season through 2021.
The reason the Cardinals felt compelled to go that high was their need for speed and defensive competence. They were a below-average fielding team and one of the worst baserunning groups in the majors last season. General manager John Mozeliak said Fowler was the team's No. 1 target all offseason.
"It was an honor just to be considered to be in the Cardinals organization,'' said Fowler, who will wear No. 25 in honor of his mentor, Barry Bonds. Fowler'susual 24 is retired by the Cardinals; it was worn by former manager Whitey Herzog.
Now, with the 30-year-old Fowler in center field alongside young outfielders Randal Grichuk and Stephen Piscotty, the Cardinals feel they have one of the better defensive outfields in the league.
"One of things we wanted to address was athleticism, someone who could hit at the top of the order, if possible, to allow us to have flexibility with [Matt] Carpenter, and we were looking to find someone who is extremely competent on the basepaths," Mozeliak said.
"I think we were able to accomplish that, but Mr. Fowler is more than that. There's always the baseball element, but one of the things about Dexter that excited us is he's a student of the game."
The Cardinals had discussions with the Chicago White Sox about Adam Eaton before he was shipped to the Washington Nationals for a trio of highly regarded pitching prospects. They also engaged other teams in trade discussions.
The Cardinals are aware they lost a lot of power when Matt Holliday and Brandon Moss became free agents, but Mozeliak indicated the team isn't necessarily intent on signing one of the sluggers still available on the free-agent market and any further moves would likely be "complementary" acquisitions.
It came as no surprise that Fowler turned down his mutual option with Chicago. He made $13 million in 2016, returning to the Cubs for one year only after exploring the free-agent market last winter and finding it unsatisfactory.
Fowler was due a big payday after having a career-high .393 on-base percentage and hitting 13 home runs for the Cubs last season, including a blast in Game 7 of the World Series.
He also was credited with playing better defense in 2016, after he and the team agreed he should play deeper. The result was a plus-1 in defensive runs saved, according to FanGraphs. In 2015, Fowler was minus-12.
Fowler's biggest contributions came at the top of the order, where Cubs manager Joe Maddon used to say to him, "You go, we go." Fowler's first-inning on-base percentage in 2016 was .479. He was the ignition to the Cubs' offense throughout his two years with the team.
The move comes after the Cubs signed Jason Heyward and John Lackey away from the Cardinals last offseason.
Fowler is the first free agent to sign with the Cardinals after ending the previous season with the Cubs since Mark Grudzielanek did it in the 2004-05 offseason. The Cardinals and Cubs open the 2017 season on April 2 in St. Louis (8:30 p.m. ET, ESPN).