Baltimore's quest for a championship seemed doomed from the start when long-time starting quarterback Johnny Unitas suffered a pre-season injury to his throwing arm and was replaced by Earl Morrall, a veteran who had started inconsistently over the course of his 12 seasons with four teams. But Morrall would go on to have the best year of his career, leading the league in passer rating (93.2) during the regular season. His performance was so impressive that Colts coach Don Shula decided to keep Morrall in the starting lineup after Unitas was healthy enough to play. The Colts had won ten games in a row, including four shutouts, and finished the season with an NFL-best 13–1 record. In those ten games, they had allowed only seven touchdowns. Then, the Colts avenged their sole regular-season loss against the Cleveland Browns by crushing them 34–0 in the NFL Championship Game.