Javier Assad’s command has been a staple of his big-league success. Since his transition to the rotation one month ago, it has served as the basis for his ability to give the Chicago Cubs quality starts. Coming off the deepest start of his career with eight shutout innings in Cincinnati, Assad searched for his command throughout a 6-2 loss Thursday night against the Arizona Diamondbacks. “I tried to take it inning by inning and I tried to maintain the score as low as possible,” Assad said through an interpreter.