WASHINGTON (AP) -- Mike Shanahan says the Washington Redskins have entered "must-win" territory.

The coach used the phrase Monday to describe the upcoming game against the Carolina Panthers.

The Redskins dropped to 3-5 Sunday with a 27-12 loss to the Pittsburgh Steelers, the first lopsided defeat in rookie quarterback Robert Griffin III's career.

The Panthers make for a good "must-win" opponent with their 1-6 record, but the Redskins must also avoid looking ahead to the bye week that follows.

After the bye, the schedule gets tough -- with three consecutive NFC East opponents followed a game against the Baltimore Ravens.

Shanahan cited injuries as contributing to the defense's struggles. The Redskins rank last in the NFL in defending the pass.