There's no overlooking Corbin now, though. That's what happens when you start off the year 7-0 and your 1.44 ERA is second in the National League, only behind some guy named Clayton Kershaw.
"He's been dealing, man," D-backs catcher Miguel Montero said.
Corbin impressed Arizona's coaching staff during Spring Training in 2012 with not just his pitching, but his quiet, confident manner. So when the team decided to move Josh Collmenter to the bullpen, Corbin got called up from Triple-A Reno.
"I just knew if I went out there and did my job, I always knew that I could pitch and do well. So I just focused on what I was doing, and it was a matter of time until I got up to this level," Corbin said. "I just credit last year for a lot of my success. I learned a lot, had some failures, some high moments, but it was a good thing to take into this year."
In two stints with the D-backs, Corbin made 22 appearances (17 starts) and was 6-8 with a 4.54 ERA. Not bad for a rookie, but certainly nothing like what he's shown this year.
Corbin's 2.5 Wins Above Replacement mark is third in the NL among pitchers behind Kershaw and Mets phenom Matt Harvey. Heading into Spring Training this year, Corbin had to battle top prospect Tyler Skaggs and Randall Delgado for the No. 5 spot in Arizona's rotation.
"It's impressive," D-backs Opening Day starter Ian Kennedy said. "You're talking about a guy that people said might barely make the team in the fifth spot. He pitches well in Spring Training, but it's Spring Training. Then the season starts and he's doing pretty good now. He's on a roll now. I'm impressed."
The biggest key for Corbin seems to be the development of his slider, a pitch that has taken a huge leap in effectiveness from 2012 to '13. Corbin said when it came to the slider, he had to adjust from Minor League baseballs -- where the seams of the ball are a little more raised -- to the smoother ones they use in the big leagues.
Whatever the reason, Corbin's slider has become lights-out and he is throwing it with greater frequency. Last year, he threw the pitch 16 percent of the time, while he's using it 22 percent of the time this season.
Combine an improved slider with slightly more velocity on his fastball and better command overall, and Corbin has literally been unbeatable this year.
"He's got a good one," Montero said of Corbin's slider. "Especially when he's got that fastball command. He's able to get it in and get it out. They start looking for a fastball in or a fastball away, and then there comes a slider with the same arm speed. It's hard to lay off that good of a slider."
Just ask the Rockies, who earlier this week were on the receiving end of Corbin's first big league complete game, which came at Coors Field no less.
"He hits his spot," Colorado third baseman Nolan Arenado said. "When he threw the slider or whatever, it was perfectly on the plate. You never saw him in front of it. He was either on it or right behind it."
So now the question with Corbin has gone from can he be successful in the big leagues to can he continue his success?
There are no secrets in baseball, so opposing teams will continue to try to probe for weaknesses, and Corbin will also have to deal with the increased media attention he has been getting.
"I just hope he can stay grounded and just keep doing what he's doing," D-backs manager Kirk Gibson said. "He's so young, it's all new to him. He doesn't really know what he's getting into as far as that [attention] goes. He just doesn't. We all have to learn along the way. He's a level-headed kid, he's a humble kid."
The same quiet confidence, self assurance and even-keeled approach that helped him get to where he is right now is also Corbin's best asset when it comes to continuing his success.
"I just think my personality is that I stay the same," the pitcher said. "I've been like that my whole career coming up, and I don't think I'm going to change no matter what happens. I think the best way to do it is just to be myself, and if I get more attention, that's a good thing. But you still have to go out there and do your job, and that's what I'm going to be focusing on."