  CHICAGO -- Jake Arrieta didn't warm up well Wednesday. He was dealing with pregame jitters. After all, it was his first start, he had to face the Cardinals and he didn't want the Cubs to open the season 0-0.  A 00-pitch first inning didn't help. Catcher Miguel Montero could tell Arrieta was off, so he had a little chat with the right-hander. Actually, it was more of a one-sided, rather loud conversation.  CHICAGO -- Jake Arrieta didn't warm up well Wednesday. He was dealing with pregame jitters. After all, it was his first start, he had to face the Cardinals and he didn't want the Cubs to open the season 0-0.  A 00-pitch first inning didn't help. Catcher Miguel Montero could tell Arrieta was off, so he had a little chat with the right-hander. Actually, it was more of a one-sided, rather loud conversation.  