After narrowly losing out on pitcher of the month in April, Ervin Santana has been a substantially different pitcher in May. No one expected him to finish the season with a sub 1 ERA. However, for his entire career, he's been just under 3 BB per 9 IP. In April, Ervin walked 10 over 5 starts in 35 innings, which would be slightly lower than his career BB per 9 IP.
In May, he has already walked 15 over 4 starts in just 26 innings, a disturbing 5.2 BB per 9 IP - almost double his career rate. I'm not ready to stick a fork in him just yet. After all, in two of those starts, he was able to pitch around those walks and not allow any runs. In two, he was not and allowed 5 and 6 runs respectively. Clearly, no pitcher can be consistently effective at the MLB level walking 5 guys a game.
If this were still April, I might chalk it up to cold weather. But, I don't believe cold weather has been an issue in any of his May starts. I did not see his start this afternoon, but did see the other 3 he made this month. A lot of those walks contained multiple pitches that were not close. Some were, of course, but many were not. I don't think he's being squeezed or "just missing" for the most part. In a lot of cases, he's missing badly. That's also disturbing. If he misses out of the strike zone badly, he could start missing IN the strike zone badly. You only need to ask Kyle Gibson what happens if you do that.
The Twins are a long shot contender even if Ervin Santana pitches as well as he did last year. If he continues to walk 4-5 guys a game, the Twins have no shot. The Twins and Santana need to get on top of this before it becomes a bigger problem.