PHOENIX -- Five years ago, at the tender age of 16, Michael Ynoa was signed to a then-record $4.25 million bonus by the A's.
Since, the Dominican right-hander has faced many challenges so early in adulthood, having been limited to just 39 2/3 innings in four seasons because of elbow issues that culminated in Tommy John surgery in 2010. But on Thursday, with those troubles behind him, Ynoa finally made his first step into big league camp and exuded a child-like smile that for so long was hidden by frustration.
"I'm so excited for him, just because of all he's been through," said Keith Lieppman, A's director of player development. "Now he has the opportunity to show everyone what he can do. He went through so much rehab and scans and tests and programs, and he would get back to a certain direction only to have to turn around again and reboot it. You just see someone who has gone through a whole lot at such a young age."
Ynoa's journey to camp, much like the one he's traversed in his career, didn't come without a setback. The pitcher, now 21, was hit with chicken pox -- "bad, very bad," he said -- right before he was scheduled to travel to Arizona, delaying his arrival in camp nearly two weeks.
As a result, Ynoa will be slightly behind other pitchers, but he and manager Bob Melvin anticipate his Cactus League debut to come in about two weeks.
Ynoa, already equipped with an explosive fastball, will bring a new pitch to the mound, inspired by watching Roy Halladay on television.
"I'm trying to learn the cutter," he said.
"With his arm angle, he's got a good breaking ball and the ball comes out good, and this just adds another dimension to his game, gives him a different look," Lieppman said.
This will be Melvin's first look at Ynoa, whose wiry 6-foot-7 frame is hard to miss.
"When I saw him, he was ducking into the training room," Melvin said. "I didn't realize he was quite that size. He looks like he could reach out and put the ball in the catcher's glove."
The A's need to see Ynoa throw strikes this spring, something he struggled with in his first full professional season last year.
Having fully recovered from his Tommy John surgery, Ynoa was able to make all of his starts on turn once the short season began in June. He made six appearances with the Arizona Rookie League affiliate and was then promoted to short-season Class A Vermont, where he had eight outings.
Between the two teams, Ynoa struck out 25, but he also walked 25 in 30 2/3 innings, posting a 6.46 ERA in the process. But he showed improvement at the A's fall instructional league camp, where Lieppman and Co. finally caught a glimpse of the 16-year-old kid they signed back in 2008.
"We were able to get a little bit of a sense of what he was like when he was loose and free, like he was when he first signed," Lieppman said. "Before, he was pitching very tentatively coming back from surgery and rehab, and he never really let it go, so I think we're going to see some good stuff over the next few weeks and years.
"I'm looking forward to seeing him compete. He's never had any failure. He's never had any success. To be in Arizona, we just want him to be able to reach a certain level physically and mentally. There's going to be some really positive things, but he's also going to have to learn how to adjust.
"You're going to have some ups and downs no matter what level you're at, and he's never really gotten to experience that -- just the ups and downs of rehab, but not competition. We don't want him to be overwhelmed by expectations right now. Just to stay healthy and take things as they come."
Should health remain on Ynoa's side, the A's still expect big things from him. That's why they protected him from the Rule 5 Draft this winter and placed him on the 40-man roster, allowing him to come to big league camp this spring. In doing so, the A's also seemingly sped up his developmental path, as Ynoa will now only have three years to make the A's Major League roster before he will be out of options.
The A's could make Ynoa a reliever to hurry this process, but the plan for now is to continue to have him start.
One of the few familiar faces surrounding the youngster on Thursday was A's coach Ariel Prieto, who worked with Ynoa during his first three years in the organization.
"I remember the first bullpen he threw," Prieto said, "and you could see him having a great projection, becoming an All-Star in the Major Leagues. The guy looked like a veteran pitcher, with good control, good stuff, but then he had all those injuries. I'm so happy for him that he's here. He's a great guy, he's got a great attitude and he works hard. I hope he shows everyone what he can do here."
• A rare snowfall in parts of Arizona on Wednesday, including the D-backs' Spring Training home at Talking Stick, forced the club to hold its Thursday workouts at the A's Papago Park, after Oakland finished its workouts.
Former A's pitchers Brandon McCarthy and Trevor Cahill, now with Arizona, were the first to arrive -- early enough to grab the final two premium parking spots.
"They saved them for the team's last two Opening Day starters," joked McCarthy, whose 2012 Opening Day start for the A's came just a year after Cahill received the nod.
Also seen in red: New D-backs player Eric Chavez, who played in Oakland for 13 years, racking up six Gold Glove Awards at third base along the way.
• Infielder Eric Sogard missed Thursday's workouts to attend the funeral of his grandmother.
Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB.