Len Dawson might have been the biggest miss by the organization in their early days
Other than Johnny Unitas, the biggest miss in draft history by the Steelers is Len Dawson. He was drafted fifth overall by Pittsburgh during the 1955 NFL Draft. He was given few chances to start for the club during his time in the Steel City. You would imagine that being the fifth overall pick would have warranted a shot, but the team did not see it that way.
Other than some relief work and coming in when certain players got hurt, Dawson was never out there on the field for the Steelers. After years of being a laughingstock in the league, Pittsburgh became desperate to become somewhat noticeable. They would trade Dawson away only two years after drafting him for Hall of Fame quarterback, Bobby Lane.
Lane did play for the black and gold for a handful of years, but he could not drag the team to any semblance of a championship. Dawson would not become an immediate success story that worked against the Steelers. It would take almost another four years until Dawson ended up with the Kansas City Chiefs.
Most of his success in the NFL came with the Chiefs and he was able to win MVP of the Super Bowl there. It might have taken nearly six seasons for Dawson to finally become a quality starting quarterback in the NFL, but he was able to get to that point. The Steelers showed desperation be trading away Dawson and never giving him a shot as a starter and that was another missed opportunity.