The 24-year old Niesen had a 3.63 ERA as a starter, which masked his 41 walks against 38 strikeouts, which simply isn't good enough. In his short professional career, Niesen has had trouble throwing enough strikes. It appeared that Niesen had figured something out in St. Lucie last year when he walked just 6.7% of opposing batters, but he's gone backwards this year, with a walk rate of 17.3%, his highest since 2007! The chart below shows Niesen's walk and strikeout rates in his career.
Carson's over numbers at St. Lucie were marred by a really ugly start to the year, when he had a 8.27 ERA after his first five starts. The chart below breaks his season into two pieces, Opening Day-5/1 and everything after.
|April + 5/1||16.33||29||15||15||2||14||15||8.27||16.85||15.73||.403||1.07|
I would have kept Carson at St. Lucie for a few more starts to prove that his recent mastery was real, but the Mets clearly felt that balancing the interests of both pitchers, Carson and Niesen, the time for a promotion was now. The early returns aren't great, as Niesen walked two guys in 1.1 innings of relief on Friday, but lets see how this plays out the rest of the year.