The NFC East rivals meet in the opening round of games of the 2013 season tomorrow night.
The tight end told the team's official website: "Washington is going to be a great challenge. They won the division last year and they have a lot of pieces on defense. They want to put pressure on the backfield.
"London Fletcher has had a career that everyone respects. He's been so great for so long, and he's still playing at a high level. Brian Orakpo and Ryan Kerrigan are very disruptive players coming off the edge for Washington and they play a great scheme. It's definitely going to be a big challenge for us.
"We're excited to see how the offense performs on the field together for four quarters. It's time to come out of the gates and play great football and get the season started the way we want."
Casey joined the Eagles in 2013 after playing for the Houston Texans between 2009 and 2012.