Buffalo settled for a field goal.
Marrone said Manuel wasn't entirely at fault, but also didn't let him off the hook either, suggesting the rookie needs to stop pressing.
"We know the quarterback didn't play that well yesterday, and he knows that. And we have to get him to play better," Marrone said. "Now, do we expect him to play better than he did last game? Absolutely. Will he play better? Yes. Yes he will."
Manuel was defensive when asked if he regarded his performance as a setback.
"That's your assessment. I don't think so," he said. "I thought there's always some good to take out of every game. And we're just going to build on that."