Peterson pitched 4.1 scoreless innings, allowing three hits and two walks while striking out four in a 5-0 win Sunday against Arizona. He did not factor into the decision.
Peterson did not allow a runner past second base in his first start of the season. The lefty wasn't exactly efficient, needing 80 pitches to get through 4.1 innings, but he got the job done. After not making the team out of spring training, the 26-year-old has pitched very well to start the season and has yet to allow a run in 8.1 innings. He is scheduled to start against the Diamondbacks again on Friday in Arizona.