Viewers of HBO’s "Hard Knocks" had seen the immature side of rookie TE Martellus Bennett, who not only was struggling to make a consistent impact in early training-camp practices but also was seen mocking TE coach John Garrett and arguing with him over the little details it takes to be a good pro. But our sources say — and even the most recent "Hard Knocks" confirms — that Bennett has made considerable progress since the end of camp. He has looked good during preseason games and appears to have begun harnessing his immense physical abilities and applying them on the field. The mental part of the game has given Bennett the most trouble to date, but he has shown enough recently for the coaching to believe he can contribute right away. Bennett has credited starter Jason Witten for giving the rookie a heavy dose of tough love, getting on him to learn the playbook better and stay focused. Witten has credited former Cowboys TE Dan Campbell for being tough on him early on, and that the treatment helped make Witten a better player down the line.