Jim Haslett will get a chance Friday to see what kind of an impact offseason additions Ryan Kerrigan, Barry Cofield, Stephen Bowen and Jarvis Jenkins will have on the Washington Redskins’ defensive front. And the defensive coordinator will get to see what kind of a cornerback tandem DeAngelo Hall and Josh Wilson form. But he’ll have to wait a bit longer before he can get a view of the complete picture.

When the Redskins take on the Pittsburgh Steelers in the preseason opener, they will be without starting strong safety LaRon Landry, and also could be without starting free safety Oshiomogho Atogwe, who missed Monday, Tuesday and Wednesday’s practices while nursing a hamstring injury.

Landry has spent all of training camp on the Physically Unable to Perform (PUP) list while working his way back from an Achilles’ tendon injury that forced him out of the final seven games of 2010.

“I’m looking forward to someday having the whole unit together,” Haslett said. “It’s been back to the second half of last season that we’ve been kind of piecing things together.”

Haslett isn’t concerned by the absences of Atogwe and Landry from an evaluation standpoint. Having coached Atogwe in St. Louis early in the free safety’s career, and having worked with Landry last season, Haslett knows what both can do.

“I’m not worried about it,” Haslett said. “I’ve been around [Atogwe] enough to know that when we play, he’ll be ready to go, and the same thing for [Landry].”

If Atogwe doesn’t play, Chris Horton likely will start in his place. Reed Doughty has taken all of the first-team snaps at strong safety. Rookie DeJon Gomes has seen action at both positions, but remains a work in progress.

The only position on the defense that has yet to be determined is who will start at inside linebacker next to London Fletcher. Last year’s starter, Rocky McIntosh, and second-year player Perry Riley have been competing for that job.