3. CB Keenan Lewis
I remember being very hopeful that the 2009 NFL Draft class would turn out to be a great one for the Steelers. Coming fresh off a Super Bowl win, Pittsburgh still managed to have 4 selections inside the top 100 picks and their roster was already strong.
However, things didn't exactly go as planned. First-round pick Ziggy Hood proved to be a bust and their next selection, OG Kraig Urbig, was a disappointment in Pittsburgh. While Mike Wallace was a hit early in his career, fans really warmed up to Keenan Lewis by his third season.
By year four, the lengthy cornerback and former 96th overall pick looked like an answer on the boundary. He started all 16 games in 2012 and helped shut down his side of the field while showing his impressive ability in run support.
Unfortunately, Lewis peeked at the wrong time, and Pittsburgh couldn't retain him. He hit free agency during the 2013 offseason and signed a five-year $25.5 million contract with the New Orleans Saints. Lewis earned 6 interceptions over the next two seasons on his new team, but back injuries forced him to retire early.