TORONTO -- For two seasons, Ricky Romero was the ace of the Toronto staff.
But after a rough season in 2012 and a tough Spring Training, J.A. Happ found himself replacing Romero in the rotation. The former ace was subsequently shipped off to Dunedin, Fla., to work on his mechanics in order to get back to Toronto.
On Friday, Romero made his triumphant return to the mound at Rogers Centre after extensive work with Blue Jays roving pitching instructor Dane Johnson.
"It's going to be the same Ricky. He's the same guy," Johnson said prior to Friday's 4-0 loss to the Mariners. "We've taken what's best in that guy and polished it up as best we possibly could. We didn't reinvent him. We just took what was missing and implemented it, and got back to the basics in what needs to happen in that delivery."
Romero went four innings in his season debut, allowing three runs and striking out four. He faced the minimum number of batters through three frames, but a two-run homer and a loss of command in the fourth paved the way for an early exit.
Johnson and Romero went through an extensive amount of video, including the left-hander's first couple years with Toronto's Class A team in Dunedin in 2005 and '06, with the purpose of breaking down where the ball should come from.
The duo spent countless hours dissecting his delivery, along with his progression and regression over time, and after several weeks, they believe his delivery is consistent and repeatable.
"[His delivery is] much more consistent," Johnson said. "He's working down through the ball, he's over the ball and he's driving it down. He's not cutting the ball off or working side-to-side."
Romero worked hard on his delivery, with only subtle changes. According to Johnson, the main idea was to make sure "to cross his T's and dot his I's."
The duo added a tap for a timing sequence from his full windup, focused on making sure his shoulders are lined up with home plate, and that he's aggressive out of his front side and finishing pitches down and through the strike zone.
"It was more attention to detail on his throwing programs, on his sides, his delivery, and paying attention to those," Johnson said.
However, it took awhile for Romero to get down to the work he needed to do. He spent so much time in the offseason preparing himself for Spring Training that the news of not making the team struck him harder than he thought.
"I had so much anger and so much disappointment," Romero said. "A whole month where you're away from everyone, and at the beginning it's tough to realize what I need to really work on. And it took me a couple days."
With all the work in Dunedin, Romero pitched in only one Minor League game, something that Johnson believes isn't a concern.
"He has enough reps under his belt doing things properly technique-wise and mechanically, where he can worry about the hitter and what's going on at home plate," Johnson said.
"From Day 1, Dane told me, 'You're going to commit to this or you're not.' When he sat me down and told me that it was just time to work, that's what I did," Romero said. "Every four or five hours that I was there, I was committed."
The work certainly paid off in his only Minor League start, as Romero induced 16 ground-ball outs, struck out four and didn't walk a single batter.
Evan Peaslee is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.