The Redskins failed to score a touchdown and put up just six points against the 49ers as they fell to 3-8 in their season.
"It wasn't the greatest of weeks," Morris told the Washington Post. "But you're gonna have that sometimes.
"Just because you had a bad week, not that we had a bad week, but sometimes if you have a few bad practices or a few bad [practice] periods doesn't mean you're gonna have a bad game.
"But like I said, today we just didn't show up for whatever reason. I don't know what it was."
Mike Shanahan's side face the New York Giants on Sunday.