Jason Campbell (2005 – 2014)
Sadly for Jason Campbell, the performance was never really there. He is just one of those quarterbacks who was always expected to break out any season, but unfortunately it never ever happened. There were many occasions that he was on top of his game but had a career-low 75.8 QB rating in eight games. Just before he announced his retirement, Campbell says that he was approached by several teams but turned them down.
Randall Cunningham (1985 – 2001)
We always give credit where credit is due so yes, Cunningham was a superb athlete and a bit of a pioneer as far as quarterbacks who were mobile and able to use their legs. Even though there were some remarkable highs, including that near-perfect season with the Vikings in 1998, there was still a lot of stopping and starting. After the 1990 season, Cunningham spent more than a decade in the NFL but was never the full-time starter two years in a row from that point onwards. Sadly consistency was not part of his vocabulary.