KANSAS CITY -- The Kyle Zimmer story has been one of the most fascinating and well-documented tales in recent Royals history.
Zimmer, the Royals' first-round pick in 2012, appeared to have all the talent to be a top-of-the-rotation pitcher. But he has stood by and watched his career besieged by injuries -- four surgeries to date ranging from his right shoulder to thoracic outlet syndrome -- and numerous comebacks, none of which offered much promise.
But a glimmer of hope emerged last fall when MLB.com spoke to Zimmer upon his completion of the revolutionary Driveline Baseball program in Seattle. Zimmer reported from the Arizona instructional league that for perhaps for the first time in his professional career, he felt no pain or discomfort after throwing off the mound. He was amazed.
The Royals and assistant general manager J.J. Picollo had suggested, almost as a last resort, that the oft-injured Zimmer try Driveline, which focusses on strength conditioning based on weighted balls and other activities designed to regain strength and durability. There wasn't much to lose.
The Driveline experience so far appears to have been a huge success.
"I'm feeling as good as I've ever felt," Zimmer, 27, reiterated to reporters Friday. "I have definitely put in the hours. Now I can just compete and go play baseball."

When Zimmer entered Driveline last spring, the Royals took him off the 40-man roster, a move that astonished some Royals fans who may have believed the organization simply was saying "enough."
That wasn't the case at all.
"We sort of talked about all that, the roster decision," Zimmer said. "I was sitting down with J.J., and he was suggesting sending me to Driveline. And at the time, they couldn't be holding on to a roster spot just so I could take a year off to be training. They needed room for someone. I was OK with it. It made sense."
Zimmer eventually signed a Minor League deal with the Royals. When he completed Driveline, though, there were other roster obstacles to navigate. He was eligible for Minor League free agency last fall. And while procedurally he accepted free agency, he never had the slightest intention of turning his back on the Royals.
The Royals weren't turning their back on him, either.
"We obviously took him off the roster and no one claimed him [last spring]," Royals general manager Dayton Moore said. "He obviously couldn't stay healthy. It wasn't personal. We loved Kyle, but he couldn't stay healthy. But we knew he's tough-minded, and he has the right ingredients. He came to instructional league and we evaluated him last fall, and we thought he deserved the chance to be on the 40-man again.
"It wasn't just us. We based it on trying to win the negotiations based on what other teams were deciding. There were other teams willing to put him on the roster. I would rather have him fail with us than succeed with someone else. That's the play there."
Zimmer acknowledged there were other teams interested in his services. <p<> And now, Zimmer will head into Spring Training, hoping he can squeeze his way onto the 25-man roster. </p<>
Zimmer not only has had to endure numerous medical setbacks, but also the sarcasm of some Royals fans on social media. But he has overcome the setbacks and turned a deaf ear to the critics.
"My mobility is as good as it has ever been," Zimmer said. "Where in the past I kind of got locked up after throwing, I don't anymore. It used to be when I ramped up, I would start breaking down again. Now, I have no issues."
Zimmer has continued his throwing program of three to four times a week off the mound. He said his old velocity has returned as well.
"I am back to the mid-90s [mph]," he said. "To me, it was just building a whole new foundation, laying the cement, putting in the posts, and starting from the ground up, and having an extended time off to do that."
As for Spring Training, Zimmer said, "I'm not optimistic, it's just confidence. I just feel confident in where I am. I've done everything I can. I'm not really worried or concerned. I mean, I've never lost confidence in myself, and I'm still close to doing what I've dreamed of as a kid."