Nobody complained. Cecil evolved into one of the top left-handed relievers in the game, posting a 2.67 ERA in 189 outings from 2013-15.
This year, things changed. His trademark curveball flattened out. By July 20, his ERA was 6.75. And shortly thereafter, Toronto pitching coach Pete Walker issued new marching orders.
"Pete suggested that I take all the thinking out of the pitching and let the catchers handle that, and just execute the pitch they call to the best of my ability," Cecil said. "Don't shake off. Don't worry about setting guys up or anything like that. So far, it's been working."
Cecil had held opponents scoreless in 14 consecutive outings, the latest coming in Monday's 7-5 loss to the Yankees. His ERA over his past 27 games is 1.45. In that stretch of 18 2/3 innings, he had struck out 25 and walked four.
Walker said Cecil's persistent tendency to override his catcher's signs spawned the new approach.
"There'd be a lot of shaking with him, more so than other pitchers," Walker said. "That tends to take you out of your flow as a pitcher and a catcher."
Cecil's own due diligence sometimes came back to bite him, Walker believes.
"Brett is a student of the game," Walker said. "He does a lot of studying of the hitters. He takes a lot of the information we have and utilizes it. But I think sometimes that can cloud your mind as well, where you tend to think a little too much. That was the case with him. I think it was just an opportunity for him to kind of free his mind and trust his catchers and trust the process of how we go about attacking hitters."
After his tough first half, Cecil said, a couple of scoreless outings helped him regain his confidence. And for reasons he cannot entirely explain, his old curveball returned.
"He's in a better place right now as far as the spin on his curveball, the tightness of his curveball, the late-breaking action," Walker said.
"There were signs of the stuff being there throughout the season, but right now it seems to be sharper and the velocity seems to be a little bit better. Maybe freeing his mind has helped in that area as well."
Cecil isn't sure about that -- "there are a lot of things in this game that you can't explain," he said with a smile -- but he's glad both his curve and his confidence have been restored.
"You get a little confidence back and get that swag back," he said. "It's hard to go out there thinking you're the man when you've got a seven ERA."
John Lott is a contributor to MLB.com based in Toronto. This story was not subject to the approval of Major League Baseball or its clubs.