"At that point, I was like, 'Wow, this is something I wasn't expecting,'" Shelton said. "But I was enjoying it."
That was 10 years ago Friday. Last Sunday was the anniversary of his two-homer Opening Day in Kansas City that started the craziness. As fans pack Comerica Park on Friday for the Tigers' home opener, there might be a Shelton jersey or two that spark a memory.
The kids Shelton coaches as an assistant at Cottonwood High School, his old school in Salt Lake City, are too young to recall the moment. But after the crazy April, the leveling off, the midseason slump and the stretch-run demotion, he remembers that stretch as a good thing.
"At times, it feels like 10 years since it happened," Shelton said, "and at other times, it feels like yesterday. I loved it."
A decade before J.D. Martinez, the Tigers -- then coming off a 119-loss season -- thought they might have a hitter in Shelton, a stocky first baseman in the Pirates' system who was left unprotected in the 2003 Rule 5 Draft coming off a .336 average and 1.008 OPS. The Tigers had Carlos Pena, but they needed all the talent they could find.
"He was really an unknown," said Al Avila, then an assistant general manager. "The main thing I can remember is our scouting reports said he was a pure hitter who could hit to all fields, had a good eye. Really, we kind of rolled the dice on him."
The Tigers carried Shelton on their bench in 2004, and he began the following season at Triple-A Toledo. After hitting .331 with eight homers and 39 RBIs in 48 games, he was promoted to Detroit, where he hit .299 with 18 homers and 59 RBIs.
Shelton hit well enough the next spring that the Tigers released Pena, who enjoyed a 46-homer season for the Rays the following year. But nobody saw Shelton's start coming.
Shelton opened by lining a hanging slider from Scott Elarton into the left-field seats, then keeping a ball just inside the right-field foul pole for his first career multihomer game. Two games later, he sent a pair of R.A. Dickey pitches out in Texas. Shelton homered again the next day.
"He hit knuckleballs, fastballs, curveballs, he hit sliders," teammate Carlos Guillen recalled. "He hit balls in the dirt for base hits, home runs, everything that first week."
Shelton came back to Detroit a hero, hit two-run homers in back-to-back games against the White Sox, then got Cleveland's Cliff Lee for the only run in a 1-0 win a few days later. When Shelton homered again the next afternoon, he was the fourth-fastest Major Leaguer to nine homers in a season, trailing Mike Schmidt, Luis Gonzalez and Larry Walker.
All the while, Shelton insisted, he was just trying to hit the ball hard.
"There may have been individual at-bats where I would take a shot," he said, "but I don't think my approach ever changed. I knew what kind of hitter I was. I knew I wasn't the hitter that I had shown for the first month, but I knew I wasn't an awful hitter."
Shelton hit .326 with 10 homers and 20 RBIs in April. He batted .286 in May, but with one home run, expectations dogged him. The publicity, too, was something he wasn't used to handling.
"It became hard to repeat things in a manner of what that first month was like," Shelton said. "I hope that expectations after that first month didn't change to become that's what was expected of me. In my eyes, it felt a little unfair at times. To me, that's an unfair expectation of anybody.
"Looking back on it now, I probably needed to simplify things a little bit more and try to keep things consistent. I felt pressure, because we were winning and I wasn't contributing the way I thought I should."
Shelton's average finally dropped under .300 in June. He kept it around .275 through July, but when the Tigers saw a chance to add a veteran hitter, they acquired Sean Casey at the non-waiver Trade Deadline. Shelton went back to Toledo, an April sensation who became a Mud Hen in August.
"When it first happened, one or two years after, people asked me if I was upset with Jim Leyland and [then-GM Dave] Dombrowski," Shelton said. "I'm not. They gave me an opportunity to play in the big leagues. They felt like they could upgrade at that position and went about it. At the time, I was very upset."
Shelton made it back as a September callup, but he played sparingly. Shelton made it back to Detroit for the AL championship ring ceremony the next Opening Day, but he spent the entire 2007 season in Toledo. The Tigers traded him to Texas the next year, and he was out of pro ball a few years later.
In the end, the crazy month was just that. Still, Shelton's grateful for it. He takes lessons from that time into his coaching job. And when his players ask about his career, he talks well of it.
"Even though I only played for him for a year, people always ask me what it was like playing for Jim Leyland ... Are you mad at him?" Shelton said. "Why would I be mad at him? If he asked me to run through a wall for him today, I would do it."