Griffin and new Washington coach Jay Gruden both admitted the quarterback had become too concerned with what others thought of him and his play, but said now Griffin understands that it's just part of the NFL.
Criticism of Griffin intensified as he and Washington struggled last season. His completion percentage, yards per attempt and touchdown to interception ratio all fell significantly from his 2012 Offensive Rookie of the Year-winning season, and the team went 3-13 a season after winning the NFC East.
"I learned not everyone is going to like you. That's the nature of the business, that's the nature of human beings. There are people in this room that don't like me. You just have to move on from that stuff. Jay being here has helped me grow. My family has helped me grow. ... Those things come with the territory."
Last month, Griffin tweeted a message to critics, telling them to keep doubting him. In three games this preseason, Griffin went 13-for-20 for 141 yards, no touchdowns and three interceptions.
Washington opens the season Sunday at the Houston Texans.
- Ben Estes