New England Patriots quarterback Tom Brady has warned his teammates that anything other than their best efforts will not be good enough come the regular season.
Brady told radio station WEEI: "The margin of error is always slim in the NFL, as we know.
"When you don't play good football on the road against teams that have superstar-quality players at a lot of positions, that's the way it goes.
"And it doesn't take much. And it doesn't take much in a half to get down like we got down. Things just happen quickly."
New England open their regular season campaign against the Buffalo Bills on September 8.