BALTIMORE -- It was one of those sleepy early spring mornings at Ed Smith Stadium, the days when just pitchers and catchers were required to be on the back fields when manager Buck Showalter saw it.

Lefty Zach Britton was throwing just for the second time in camp, a non-event in most cases, but vice president of baseball operations Brady Anderson had gone on all winter about Britton's offseason.

"You're going to love what this guy is doing when he comes to camp," represented the gist of what Anderson said to Showalter.

"And I went, 'There it is,'" said the typically stoic Showalter. "I got real, I don't want to say giddy, but I was like, 'OK, this might be a real serious weapon for us.'"

Britton had a fantastic spring, causing opposing scouts to salivate -- and some to grouse about their clubs passing on the lefty, who was thought to be trade bait at last July's Trade Deadline -- and the Orioles immediately took notice. While the 26-year-old was, on paper, part of the starting-rotation competition, his early short stints were enough to convince the organization that -- barring any injuries -- he was headed to the bullpen.

"It was like, 'He was a different guy out there,'" a rival scout of Britton, who hit 98 mph on some stadium radar guns and allowed one earned run over 10 2/3 spring innings, striking out 11. "Last spring, he was throwing [in the] high-80s, and it was flat. He was one of the best pitchers I saw in Florida this year."

What has changed for Britton, who has thrown six scoreless innings since making the O's Opening Day roster, is equal parts mental and physical.

Last fall, as a September callup, Britton was thinking about getting back on the weighted-ball program he had abandoned the past few years. Encouraged by former pitching coach Rick Adair to seek out Jamie Evans -- one of the brains behind the Velocity Program -- while the team was in Toronto, Britton never got the chance. But he made up his mind that he was going to give the program another go. After having a set of weighted balls sent to him in September, Britton got a hold of his old Weatherford (Texas) High School coach, Flint Wallace, in November to set up some of his old programs.

"I think the key is shoulder strength and range of motion," Britton said. "When I was hurt, I lost it. I didn't do it going into 2012 or '13. I tried to do it last year and it just didn't feel comfortable, my arm still wasn't there physically to where I could do it and not reinjure myself. This year I said, 'You know what? My arm doesn't feel as good as it used to. I have nothing to lose; maybe this is the key to getting me back to where I was.'"

Things had changed from when Britton had originally done the program in high school, with his former Major League pitching coach, the very unorthodox Tom House, changing a lot of his methodologies. But the intent, to strengthen the shoulder and increase the range of motion, was the same.

Britton employed the same program the Blue Jays have adopted in their Minor League system, the one that got Steve Delabar back to the Majors and that has also been picked up by other big leaguers like Brett Cecil. There's a set of colored weighted balls that are two pounds, one pound, six ounces, five ounces and four ounces. Britton travels with them during the season, and the guys in the bullpen have taken to using them as a means to warm up.

Britton doesn't throw the weighted balls during the season, just in the winter as a way to build up strength. And if you glance over at the Orioles' bullpen around the fifth inning, you might see a reliever or two doing arm swings with one of the colored weighted balls. Starter Miguel Gonzalez is also a fan.

"My arm started feeling really good this winter," said Britton, who had added velocity through the program. "And with that and Brady's workouts, I started to get more confident."

To explain how Britton temporarily lost faith in his abilities is a familiar tale for young pitchers, particularly those in the O's organization, as the club has struggled to develop Major League arms in the rugged American League East.

Britton had a fantastic start in his rookie season in 2011, winning five of his first six decisions and pitching to a 2.89 ERA over his first 10 games, but he landed on the disabled list with a strained left shoulder that August. The shoulder issues continued the following spring, when Britton's shoulder inflammation prompted a platelet-rich plasma injection in his bursa sac, a recommended therapy by noted surgeon Dr. James Andrews that forced him to start the season on the DL. Britton went 5-3 with a 5.07 ERA in 12 games (11 starts) for the Orioles that season, spending the bulk of the time with Triple-A Norfolk. He competed for a rotation spot last spring, but his velocity was down and Britton never looked right in camp, a point of contention in the organization that dangled him -- along with now-departed Jake Arrieta -- as potential trade chips later that summer.

After starting the season in Triple-A Norfolk, Britton was called up for a few short stints, pitching to a 5.45 ERA in seven big league starts in 2013. Simply put, he looked lost -- physically weak and mentally drained, an-all-too common occurence for young pitchers, including ace Chris Tillman.

"Speaking for me personally, you get here and you have all these advanced stats and different numbers, I can't even tell you what they mean, and you are supposed to pitch according to them," Tillman said. "And you don't even know what any of it means, really. When you simplify it, when you stick to your strengths -- which I think [Britton] is doing now -- it just goes to show what you are capable of. It's fun to watch him pitch now. I enjoy it. Watching the swings these guys take."

Healthy and confident pitching out of the bullpen, Britton is thinking less and relying on his sinker more. Gone are the days when he would obsess over the opposing teams lineup on nights he started; nowadays, Britton doesn't know if he will get into the game until a few minutes prior.

"It's just teaching me to trust my stuff a little more coming out of the bullpen," Britton said. "Being in the big leagues, throwing the ball well, being confident [are all factors]. I'm getting used to the bullpen. Obviously, I'd love to be a starter, but if that's not in the cards for this year or next year, you make do with what you got. And for me, that's being the best reliever I can be. That's the only focus I have right now until I'm told I'm in a different role."

If he keeps pitching like this, Britton could very well find himself in a new role: as one of Showalter's late-inning options.

"Sure," Showalter said on if that was a plausible scenario this season. "It's all about accumulating trust, and he's on his way."

"I think I have a long way to prove that, but it's my goal," Britton said. "We have a long season, I know there's going to be hiccups along the way. Dave [Wallace] and Dom [Chiti] have told me, 'Hey, this is a six-month process, don't get wrapped up in each individual outing. Turn the page as quick as you can, and focus on every 10 outings. Grade yourself based on that. Every 10 outings, what do you feel like? And then focus on the next.' So I'm just taking it day by day and trying to be the best I can be every day, because it's still a learning process for me."

Tillman, who was impressed with Britton all spring, doesn't care where he is so long as he's in an O's uniform.

"He'd be a force anywhere we put him right now, I think, because his confidence is back, he's throwing his sinker for strikes," Tillman said. "I stood in a couple of his bullpens in Spring Training, it was impressive. Now that he's got his confidence back, he knows what he needs to do, I think wherever we have him, whoever we put him, I think he's going to keep on doing this."