Manziel was captured by TV cameras chuckling and smiling during the first half of Sunday's game at Tennessee. The Browns were trailing 28-3 at the time Manziel was shown.
Cleveland rallied for a 29-28 win in the largest comeback in NFL history by a road team.
Pettine says he wasn't sure of the context of Manziel's behavior, but added ''down 28-3, the way we were playing, I think you could term how we were playing laughable.''
Manziel was caught by cameras during the preseason giving the middle finger to Washington's bench during a game. Pettine said the young QB has to be wary of being watched ''but still I don't consider it a big deal.''
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