SAN DIEGO -- Max Scherzer was preparing to head out to the seats to chart Triple-A Tucson's game Saturday in preparation for his start the following night when he heard that he was headed instead to the big leagues.

"It definitely caught me by surprise," said Scherzer, who caught an early flight and arrived in San Diego at 8:30 a.m. Sunday.

After watching Yusmeiro Petit throw 2 1/3 innings in long relief during their 13-inning game with the Padres on Saturday, the D-backs realized they needed some help in the bullpen, so they optioned Petit to Tucson and called up Scherzer.

"Primarily, the next few days, the thing that he brings is if we do have a long game he can pitch some innings," Arizona general manager Josh Byrnes said. "He also has some experience pitching in a shorter role, most recently in the Fall League."

Scherzer was the 11th overall pick in the 2006 First-Year Player Draft, and signed 11 months later. He started his professional career last year with Class A Visalia, and after dominating California League hitters in three starts he was promoted to Double-A Mobile, where he made 14 starts and was 4-4 with a 3.91 ERA.

A starter by trade, Scherzer pitched in relief last year in the Arizona Fall League.

"For me, it's a quick change," Scherzer said of moving between the rotation and bullpen. "It doesn't take a lot for me to go back and forth. If my ticket is in the bullpen, then I can do that. For me, it's just pitching; it's a little different style of pitching, but it's still pitching, so the same principles still apply."

Whatever Scherzer has been applying in Tucson, it worked.

In four starts, the right-hander did not have a decision, but his ERA was a minuscule 1.17 and he struck out 38 while walking just three in 23 innings.

Scherzer impressed the big league staff during the spring, and when he was optioned from camp, he was asked to improve his secondary pitches, something he was able to do while leading the Pacific Coast League in strikeouts.

"I think even how he was doing it," Byrnes said. "I think that was one of the impressive things about Max. He's a competitor and wants results, but he was also very aware of development. The numbers were extremely good, but again, I think the thought process behind it, he was sort of aware of things he needed to do to be successful in the big leagues, and doing it in games."

Scherzer's fastball usually sits at around 93-94 mph and can touch 97 when he starts. Out of the 'pen, it's probably a tick higher. That's led to some speculation that he might be better suited to be a closer than a starter. The fact that he will begin his career in the big leagues, though, is more about the team's current need than a sign of where Scherzer's future lies.

"In the long term, I think with any pitcher we would sort of give starting every opportunity to be successful," Byrnes said. "He's responded. He's really done quite nicely. We've gotten him through the system in Double-A and in Triple-A and even in Spring Training. We're optimistic that he can be a quality Major League starter, and probably prefer that that's the focus at this point."

One of the reasons for Scherzer's success this year has been the way he's been able to locate his slider and changeup. Though the change is probably his second best pitch, his slider isn't that far behind, provided he's able to be a little more consistent with it.

Having D-backs catcher Miguel Montero in Tucson on a rehab stint catch Scherzer helped in his development, as he threw the changeup at any time in the count.

"I felt like it was a huge difference in my game, giving me something to get hitters off my fastball," Scherzer said. "I was throwing all my pitches for strikes and Miggy was calling a great game for me. We were mixing up the pitches and everything, and it was great to work with him."