The results were mixed. For four innings, Teheran shut down the Blue Jays, allowing just one hit. But his command soon faltered, and he didn't make it out of the fifth inning. Manager Fredi Gonzalez said it was a typical start for a young pitcher, but he was pleased to see Teheran throwing a better curveball this year.
"I thought last year, at times, he was just a two-pitch pitcher -- fastball, and then the changeup would be his second-best pitch," Gonzalez said. "But I saw some really good curveballs yesterday. I really, really did."
Teheran -- the No. 1 prospect in baseball entering the season, according to MLB.com -- threw his curveball much more than he did in five appearances last season.
The increase in frequency of the pitch came at the expense of Teheran's changeup, which is considered to be a better pitch. He threw just four changeups on Sunday, by far the lowest percentage of any of his Major League appearances. Catcher David Ross said he often called for a changeup, but Teheran shook him off in favor of his curveball.
"I think he has more confidence in it," Ross said of the curveball. "I was calling for some changeups, which I always thought was his best secondary pitch, and he chose to go with some more breaking balls and it was working out. That's the joy of working with a young kid who's got some confidence."
Blue Jays manager John Farrell said he was surprised by how often Teheran threw the curveball, and it appeared several players were as well. In the first inning, Teheran threw right fielder Jose Bautista back-to-back curveballs, including one to strike him out looking.
Ross said he could tell that Teheran has worked on his curveball, but he said there's still room for improvement.
"It was coming off his fastball pretty good," Ross said. "It was a little firmer. It's still kind of big for an out pitch in the Major Leagues for me, but he's working on tightening it up, and he had some really tight ones going."