Rest was all the A's had prescribed Parker, after discovering the elbow soreness he dealt with for much of September and October stemmed from a forearm strain in his pitching arm. Luckily, it was all he needed, as he entered camp this weekend with full health on his side.
But Parker, still just 25 and likely destined for his first career Opening Day start this year, isn't content to go through this same cycle again. He wants to ensure his body remains just as strong at the end of the season as it feels at the beginning.
Normal wear and tear is typical -- and expected -- of any pitcher as the season progresses, but having the self-awareness to make the effort to prolonging durability can go a long way, as Parker's learning.
"At the end there, something was tired," he said, "and so other muscles were having to do extra work. I don't want to feel so worn down at the end of the year."
So Parker strayed from his normal offseason routine after totaling a career-high 197 innings last year and sought additional help at the Fischer Institute in Phoenix, where he added five pounds to his 6-foot-1 stature, reporting to camp at an even 200 pounds.
The training facility is also frequented by teammate Eric Sogard in the offseason.
"There are other guys that have done it before, and they'll tell you, 'This is a good investment to make for your career,'" said Parker, who is 25-16 with a 3.73 ERA in 61 starts over two seasons with Oakland. "I let them analyze me and break me down and tell me what I needed to do and where I could get better.
"I'm used to working out at the field on my own, so it was just a whole new thing for me. I was working with a strength coach, we were doing a lot more core, a lot more agility drills to maintain that athleticism. It wasn't like a prototypical pitchers' workout. It was more about being athletes, really."
The work continued after making the daily drive home, where Parker would prepare all of his own food, ditching the meal service he subscribed to the previous offseason.
"You start to realize it's not that hard to cut up your own vegetables," he said, smiling.
Last April was rough on Parker, but he then managed to average 6.85 innings per start over the next four months, outside of a 3 2/3-inning stint on June 29 against the Cardinals when he suffered hamstring tightness. But in September, he didn't once pitch past the sixth inning, failing to even complete five innings in two of his five starts that month.
In Game 3 of the American League Division Series, Parker was limited to 73 pitches over five innings.
"I need to have that stamina to go the distance at the end," he said. "Anything I can do to help that is big."
"He's a hard-working guy," said manager Bob Melvin. "He's hard on himself. Physically, he's not the biggest guy out there, so he probably learned something last year with the workload and how hard he had to work at the end of the season. Young pitchers find out a little something about themselves, and then you try to counteract that with maybe different workouts or eating habits. I think he's learned quite a bit and been proactive about it."