SARASOTA, Fla. -- Chris Tillman has been a hyped prospect, a talented arm unable to cash in early at the big league level and potential trade bait. But ever since Tillman's callup in July 2012, the right-hander has been nothing short of remarkable.

In the past year, Tillman has been an American League All-Star, the Orioles' ace and a pitcher with as many wins in one season (16) than the previous four combined.

Now, Tillman will add another impressive line to his resume: Opening Day starter.

The 26-year-old was officially tabbed by manager Buck Showalter earlier this spring to start Monday's season-opener against the defending World Champion Boston Red Sox. It's a tall order and one that the modest Tillman reacted to in typical fashion.

March 31: Orioles 2, Red Sox 1
W: Britton   L: Lester   SV: Hunter
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"Around the corner, he will [have a reaction]," Showalter said of the brief 10-second conversation in his office. "I'd love to ask him, 'Did you think it was going to be?' He's very unassuming. He doesn't assume anything.

"But he's one of those guys who walks out of here and, trust me, he gets it. One thing I got is his face got a little different color."

Tillman isn't one to attract fanfare, but his performance last year deserves a lot of it. In an uncertain Orioles rotation, the righty was the club's most dependable starter, posting a 3.71 ERA and pitching more than 206 innings. His previous high in the Majors? 86.

"You obviously look at his body of work and you see that he struggled early on and last year put it together," new Orioles pitching coach Dave Wallace said. "Early on just getting to know him, looking in his eye, seeing his work ethic, seeing how he prepares on days he starts, knowing him and his routine leading up to that, it's pretty good.

"And I've told Chris that. I said, 'You really prepare yourself well.' I call it a good face. You look at a guy and you know he's locked in, mentally, physically and everything to pitch. And Chris has certainly established that. There's no doubt he's well on his way to real good things."

Tillman made five spring starts, missing one due to illness, and finished his Grapefruit League campaign with 4 2/3 innings against the Rays on Wednesday night. He said he hasn't been focusing on his upcoming Opening Day start so much as preparing for the grind of a 162-game season.

"I've been focusing on getting myself ready," he said. "I think that's the most important thing. I'm happy coming out of this healthy and I'm ready to go."

"I would have liked to have made that other start, but other than that, I feel comfortable going into the season physically, mechanically and mentally."

And coming off a successful season, the Orioles see no reason why Tillman -- who will be followed by Ubaldo Jimenez -- can't continue to lead this rotation.

"I certainly see why he did [last year] just looking at his stuff, the way he prepares," Wallace said. "He had a bad outing the other day, he knew why. He had a plan and didn't let that bother him. When you put that whole package together this young man has a real good understanding of what he is, what he's about and what he wants to be."