It's been roughly eight months since then, so what about now?
"I'm back," Petrick says with an undeniable (and understandable) amount of pride in his voice. "I feel like my arm strength is back. Everything right now is back. I'm throwing harder now than I did at any time last year. My fastball, slider and changeup -- all three are coming back strong now."
That's the good news. The bad news is that Petrick still isn't likely to dive back into a live minor league game for another two months.
The right-hander, who only turns 22 in late April, was 1-4 with a 5.59 ERA in nine starts at Class-A Daytona last season. He was noticeably less effective and less enduring than the season before, averaging fewer innings per start than at Lansing the previous season when he totaled 146 2/3.
He suffered through several minor discomforts before the big one set in during mid-June, leading to a loss of both velocity and command.
After a June 12 start against Palm Beach that lasted only two innings, Petrick flew to Chicago where an MRI revealed a slight tear in his labrum.
He spent the rest of the year rehabbing in Arizona, where admittedly things weren't always as optimistic then as they are now.
"It was definitely hard staying in a baseball frame of mind," said Petrick. "I had just come off surgery, and after surgery, you're always thinking, 'Can I come back?' I was definitely worried that it would cause a setback in my career."
Those fears have since been put to rest, as Petrick has already named May 20 as the date he expects to face live hitters in an actual contest.
"My pitching, my rehab, what it entails is that I go and rehab my arm every day," Petrick said. "Every other day, I go in and throw my bullpens, which right now are at 30 pitches. All 30 of those pitches are great pitches and my arm feels strong."
Then, as if almost unsure of what else to add, "Right now, I feel great. I feel great and that's a great feeling. You know?"