Ryan Kerrigan (right) makes a tackle last weekend (Ricky Carioti/The Washington Post)

The Washington Redskins‘ defense has managed a modest seven sacks in the team’s first four games of the season. That puts the Redskins in a tie for 21st in the NFL rankings in that category, and is perhaps a significant reason for the club’s inability to slow down opponents’ passing offenses so far this season.

The Redskins are playing without their top pass rusher from last season, linebacker Brian Orakpo, who’s out for the year with a torn pectoral muscle.

Fellow outside linebacker Ryan Kerrigan has picked up the slack, with 3-1/2 sacks in the season’s first four games. But no other Redskins player has more than one.

“I think we’ve done some good things pass rushing,” Kerrigan said this week. “We’ve gotten some good pressure. We haven’t had the number of sacks we’d like to have. But those will come if we keep working.”

Defensive coordinator Jim Haslett said Thursday he thinks the Redskins’ pass rush has been better than the sack total indicates. The Tampa Bay Buccaneers focused on quick passes against the Redskins last Sunday to neutralize the pass rush, Haslett said.

“Last week it was… get the ball out of the hands,” Haslett said. “The first week they were seven-step drops against New Orleans. And then all of a sudden you play St. Louis and it’s quick, quick, quick, quick, quick. We got a lot of batted balls. You go to Cincinnati and you get a couple deep [passes] but everything else is quick, getting the ball out of your hands…. I think the credit goes to [Redskins pass rushers] that the teams are looking at you that way.”

The Redskins say the productivity of their pass rush could be a key to this Sunday’s game against the Atlanta Falcons at FedEx Field. The Falcons are unbeaten and their quarterback, Matt Ryan, is the league’s top-rated passer through the first one-fourth of the season.

“Ryan is playing at a very high level this year and he’s got great skill players around him,” Kerrigan said. “Pressure is going to be paramount for us up front…. You can see that he’s really taken that next step this year. He’s playing at the highest level of any quarterback in this league, probably, right now. He’s playing very well. They’re really firing on all cylinders.”