"Obviously the hitters [from Double-A to the big leagues] are a lot different, their approach is a lot different," Oliver said. "They don't chase as much and they have a better idea of the strike zone, so that was one of the things that I worked on when I got sent back down, just having a better command of the strike zone."
That experience is something that he hopes will serve him well Saturday night, as he makes his first major league appearance of the season against the hot-hitting Boston Red Sox.
"It's been a speedy learning curve for him," said Toledo manager Phil Nevin. "Obviously he's a talented guy and he's moved through the system quickly because of that, and I think mentally he's talented as well.
"He works hard, he gets all of his workouts done in the weight room, his bullpen sessions have a lot of intensity, and [that effort] has carried out onto the field."
While Oliver was a fast riser through the system, he was a polished pitcher entering the Tigers' system in 2009. Originally drafted out of high school by Minnesota in the 18th round of the 2006 draft, Oliver spent three years pitching collegiately at Oklahoma State.
He said that those three years played a big role in his development as a player.
"Just the experience of going to college, maturing a little bit more, doing things at the college level that I wouldn't be able to playing pro ball," he said. "So I think the biggest thing was trying to mature as both a baseball player and as a person.
"You're facing older guys, and playing in the Big 12 where there are a lot of fans, so being able to handle that pressure is something that I took from that."
He also had to deal with adversity during his college career, as he was declared ineligible during his sophomore season for dealing with an agent. He took on advisors after he was drafted by the Twins in 2006, within MLB rules, and replaced them with Scott Boras in 2008.
However, after Oliver named Boras his advisor, his former advisors, Robert and Tim Baratta, attorneys out of New York, sent a letter to the NCAA alleging that they had direct contact with Minnesota during the time period after Oliver was originally drafted.
Even though Oliver was reinstated for his junior year, he struggled during the 2009 campaign to the tune of a 1-5 record.
Once he was passed that situation and was able to focus on baseball, his true talents came to the forefront.
In 2010, between Double-A Erie and Triple-A Toledo, he threw a combined 23 starts, going 9-8 with a 3.45 ERA and 119 strikeouts in 130 1/3 innings.
Then, starting this season at Triple-A before his call-up, he posted a 4-3 record with a 3.31 ERA in nine starts.
"I've been mixing my pitches up … I've been working on my fastball command, changing speeds," Oliver said regarding his minor league success.
Even before news of his call-up reached the Mud Hens' clubhouse, Nevin felt that days he would be able to throw Oliver out there every fifth day for his team was numbered.
"Just innings [will help him improve], the more innings he throws, the crisper he is going to get with everything," Nevin said. "His secondary pitches were something that we talked about after last year and it seems like each time out they get better.
"He's still learning, but you say that about a guy who's coming out and handling Triple-A hitters, so soon that will carry over and he'll be handling big league hitters."