Complex sentence: He played in Major League Baseball as a second baseman and served as the acting manager of the Cincinnati Reds, having replaced Jerry Narron in before being replaced at season's end by Dusty Baker.
Split into simpler sentences: He played in Major League Baseball as a second baseman. Mackanin most recently served as the acting manager of the Cincinnati Reds, having replaced Jerry Narron in before being replaced at season's end by Dusty Baker.