Astros general manager Jeff Luhnow discusses the promotion of top pitching prospect Jarred Cosart, who’ll start Friday against the Rays. Decision to promote Cosart: “He has a full half season in Triple-A and sometimes the results don’t match how we feel about his performance, because we ask him to work on certain things — asking him to work on his changeup, work on his offspeed pitches to complement what we know is a pretty electric fastball. And he’s been doing that and the way we track results is not necessarily hits or runs, it’s more about what the coaches are saying and how we’re evaluating his performance. And he’s done [...]