Rapoport said Sunday on NFL Network's "NFL GameDay Morning" that Roethlisberger's frustrations boil down to two factors: losing and money.
The two-time Super Bowl-winning passer is set to make $12 million next season and $11 million the following year, when a flock of big-name quarterbacks are making upwards of $20 million annually.
Doubts linger over the ability of cap-strapped Pittsburgh to provide Big Ben the new contract he's looking for, according to Rapoport.
An auxiliary issue is the presence of offensive coordinator Todd Haley. Rapoport was told Roethlisberger was tweaked by Steelers president Art Rooney's decision to bring back Haley for a second season. Big Ben and the coach have tried to make it work, but the results -- in terms of wins -- have not been there.
Moving franchise quarterbacks is an all-out rarity in the NFL. Brightening their spirits with a fat new contract, however, is not.