The Astros appear to be going with a 6 man rotation in the future. I think this is a good idea, because it reduces the total innings that the young pitchers will throw. Lyles and Cosart are the two pitchers who are youngest and have pitched enough innings between the minors and majors that they might have to be shut down before the season is over (in order to avoid exceeding their previous career highs by too big a margin). Maybe a 6 man rotation will avoid this potential situation, and it also might make them a little stronger in their late season starts.

As for Lyles, all I can do is preach patience. His peers (by age) won't be called up for 2 or 3 more years. He is forced to develop at the ML level, which is tough for a 22 year old. The pitching talent is there, but I don't see the mentality at the same level right now.

Also, keep in mind that the Red Sox lineup frequently destroys RH pitchers. The Red Sox have the most effective lineup against RH pitchers in the major leagues. The Red Sox hitting runs created against pitchers who are righties is almost 20% better than average. The Red Sox team OPS against right hand batters is .800 (OPS+ of 123). Those stats make me worry that Cosart may have his first bad start today.