ST. PETERSBURG, Fla. — Jarred Cosart’s reward for having one of the best pitching debuts in Astros history? An immediate return to Class AAA Oklahoma City. The Astros determined pregame Friday the 23-year-old righthander would rejoin the RedHawks. Postgame, Cosart acknowledged the irony of the situation. But he sounded as determined to become a full-time Astro as he did before spring training, when the League City native said he was willing to carry teammates’ water just to be a part of the 25-man roster. “Motivation. I mean, 100 percent,” Cosart said. “I don’t think that’s a fact of them not believing that I can pitch here. They told me right [...]