The whole thing — from the time Sean Doolittle asked the Oakland A’s if he could switch from first baseman to pitcher, until the moment, during the fifth inning Tuesday night, when he made his big league debut — took only about 10 months. He logged fewer minor league innings than Stephen Strasburg, and was arguably even more dominant.

(Ben Margot/AP)

“I thought it would be more of a process than this,” Doolittle, 25, told reporters after getting called up to the majors. “I’m just as surprised as everyone else, to be honest, that the transition has gone as smoothly as it has.”

His big league debut, Tuesday night against Texas, went like this: four batters faced, four outs, three strikeouts. Twenty-one pitches, all of them fastballs, ranging from 93 to 95 mph. This came after a minor-league “career,” if you can call it that, in which he posted a 0.72 ERA, a .091 opponents’ batting average and 45 strikeouts in just 26 innings.

Doolittle had been an accomplished collegiate pitcher, going 22-7 with a 2.23 ERA during his three years at Virginia, but the A’s drafted him in 2007 (41st overall) as a first baseman. When he could stay on the field, he was a promising hitter – batting .272 with an .804 OPS and 30 homers in 879 minor league at-bats.

But a pair of knee surgeries cost him most of the 2009 and 2010 seasons, and just as he was set to come back last summer, he developed a tendon injury in his right wrist. At that point, he was close to quitting altogether.

“Two weeks after hurting my wrist, I started thinking about [retirement]. But I didn’t want to go out like that,” Doolittle said recently.

Last summer, while rehabbing his right wrist, he asked the A’s if he could start long-tossing, then if he could throw off a bullpen mound. At each juncture, the answer was yes – even though, because of his wrist injury, someone had to stand at his side and catch the ball when it came back to him. It wasn’t long before the A’s realized the talent they had on their hands. They sent him to the Arizona Fall League, where his performance was good enough to earn an invite to big league spring training camp.

“I basically missed three seasons [because of injuries], and it was hard going to the field every day for rehab,” he said. “After I made the switch, it renewed my energy for the game. And since then, I’ve loved every minute of it.”