Coach Mike Shanahan (left) has called this a must-win game for Robert Griffin III and the Redskins (Ricky Carioti/The Washington Post)

The Washington Redskins head into their bye week after they play the Carolina Panthers on Sunday at FedEx Field. The outcome of Sunday’s game will serve as a tone-setter for the conversation about the team during its bye.

If the Redskins lose, they’ll enter the bye with three straight losses and a record of 3-6. Their playoff chances would seem remote, and the bye week talk about the team probably would focus on its shortcomings on defense. There already has been some speculation about the job security of defensive coordinator Jim Haslett, and that could increase if the Redskins lose Sunday.

But if they win and take a 4-5 record into the bye, the conversation likely would be about the possible returns of safety Brandon Meriweather and wide receiver Pierre Garcon and the chances that the Redskins could make a run at a playoff spot down the stretch behind rookie quarterback Robert Griffin III.

The Redskins seem to sense the importance of the game. Coach Mike Shanahan called it a must-win game Monday. Linebacker London Fletcher expressed his agreement with that view later in the week. On Thursday, Shanahan said it was time for the team’s veteran players to “step up or shut up” to produce a turnaround by the defense in the second half of the season and improve the club’s fortunes.

“At this point, we’re midway through the season,” left tackle Trent Williams said. “We’re 3-5, obviously. We still have all our goals in front of us. We can be a playoff team if we go on a run, you know. Ultimately, if we make a good enough run, we can go deep in the playoffs and get to the Super Bowl. We’ve had a not-so-good start, not a start that we wanted to have. But at this point, all of our goals are still in front of us. We still have five division games left to play. A lot can happen in eight games.”