The Astros placed starting pitcher Wandy Rodriguez on the DL with fluid on the elbow, and called up top pitching prospect Jordan Lyles. Wandy-Rod was having a solid season statistically this season, even after his brutal start. He is 3-3 with a 3.41 ERA and 3.46 xFIP so far with aK/BB rate of 53-16. His K rate has dropped from 8.22 to 7.23 this year, but his walk rate has also dropped from 3.14 to 2.18.
Meanwhile, pitching prospect Jordan Lyles, all of 20 years old pitching in AAA this year, is 3-3 with a 3.20 ERA and 1.237 WHIP. His K rate has dropped as he moved from each level in the minors. Pitching in A ball in 2009, his K rate was 10.4/9. In 2010, pitching in AA and AAA, his K rate dropped to 7.8/9, and this year his K rate dropped to 6.3/9.
Lyles is rosterable in NL-only leagues, but I would wait a few starts before adding him to a mixed league roster.