All that I am reading says Merriweather looked tentative out there. To a lesser degree, that may have been generally true of the entire defensive backfield. They did not look lost out there, or playing out of position. It's not that bad. A number of people, after rewatching the game say that the coverage wasn't so bad.
Brett Gabbert was threading the ball into traffic out there. I don't think anyone, outside of perhaps the Miami coaching staff, saw that coming from a freshman in his first game. Iowa missed several opportunities at pass breakups and interceptions, had they been a little more on their game. Once again, I don't think they saw that coming.
What Miami couldn't do was play the deep pass, or anything that took any time do develop. Their entire approach was predicated on getting rid of the ball before the Iowa defensive line could get to the quarterback.