Romo said that he noticed the "tricks" that their secondaries and linebackers use when analysing the tapes ahead of the game.
"They grab, they hold, they've almost put a lot of pressure on the refs – whether or not they're going to call the game close or not," Romo told USA Today.
"If they get called once or twice, that's a good thing. But they're all over guys as far as using the little tricks, I guess you could say, that good linebackers and good secondaries use when they're playing man coverage."
Romo was drafted in 2003 and has played for the Cowboys his whole career.