"I've thought about it quite a bit and I can't really put my finger on it," Sonnanstine said. "I think it's going to take some time for me to reevaluate exactly what went on and figure out the things I need to change."
Sonnanstine entered the 2009 season as the Rays' No. 4 starter, carrying the momentum of a respectable 13-9 season that saw him pitch to a 4.38 ERA. Included in his 2008 work was a complete-game shutout over the White Sox and a brilliant eight-inning stint against the Cardinals in St. Louis in which he allowed just one run.
Sonnanstine appeared to be the perfect complement to the team's young rotation. Rather than being the 95-mph hurler with overpowering stuff, he was a master of deception, employing an array of pitches that he could throw from all different angles. And he seemed to be improving on the job after learning that he needed to primarily use his fastball to set up the other pitches. The right-hander's mantra was to dispatch hitters one way or the other in three pitches, which allowed him to get deeper into the games and save the bullpen. Most of all, he never lacked confidence.
But Sonnanstine got off to a slow start in 2009 and eventually got sent to Triple-A Durham. He finished the season at 6-9 with a 6.77 ERA and had the oddest of splits, which showed that left-handers hit .275 and right-handers hit .367 against him.
"I think the No. 1 key factor for me was location," Sonnanstine said. "And execution of quality pitches that weren't there like they were last year. Not being able to locate led me into trouble, and then I'd have to be perfect to have a quality outing."
Sonnanstine also wondered about his approach in 2009.
"I had a couple of conversations with [Gregg Zaun] about the location and the execution and possibly simplifying my delivery, because there's so many moving parts and angles and tempos," Sonnanstine said. "That maybe this year that approach wasn't working for me this year as well as it did [in 2008].
"That gave me a bunch of different looks and deception, and kept the hitter honest. This year, it wasn't working as well. Maybe it just affected my location more this year than last year. It's tough when I have to go back and honestly evaluate what happened."
With the emergence of Jeff Niemann and the arrival of Wade Davis, Sonnanstine's future appears to be in the bullpen. He wants to remain with the Rays whether he's a starter or a reliever, though he'd still like a shot at being a starter.
"If it's a possibility, that's something I'm going to work towards," Sonnanstine said. "Nothing against relievers, but I think starting is a role that fits me better. I've enjoyed knowing when I'm going to throw, preparing and doing research so I can do the best I can. That's where I think I'm going to be the most useful. But if something works out where I can help better in the 'pen, I'll have to try to get better at learning how to do that."
If Sonnanstine does move to the bullpen, Rays closer J.P. Howell thinks Sonnanstine can make a successful transition. Howell started for the Rays before moving to the bullpen, so he is familiar with what Sonnanstine would go through making the change.
"We both rely on location and movement," Howell said. "Best advice I can give him is that now he can go out with his best stuff. He can go out and throw his curveball a lot in an inning. He doesn't have to set it up with his fastball. So it's something where he can go into it and use his best stuff. He doesn't have to use his third or fourth pitch to set something up for later."
After the season, Sonnanstine went to Ohio to visit family and friends, and he also took time to see Mike Birkbeck, his pitching coach at Kent State.
"He helped me get my confidence up quite a bit," Sonnanstine said. "Getting back to my roots helped me realize all the things I had done to get to this point in my career."
Sonnanstine returned to the Tampa Bay area renewed after his visit home.
"Currently, I am working out harder and more often than I ever have before," Sonnanstine said. "The 2009 season was a rough year for me to say the least, and that alone has helped me push myself to get stronger, smarter and craftier. I am very excited for a great season ahead of me in 2010."
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.