Forget last season’s chatter about the Washington Redskins’ major shift in defensive philosophy. Ignore comments about this being Year 2 of the process.

Washington actually became a 3-4 team for the first time Friday night in its preseason opener against Pittsburgh at FedEx Field. That’s when the Redskins truly began to walk their big talk.

  After finally making many needed personnel changes during the offseason, Washington eventually could succeed in the defense. The Redskins have shown their commitment to the scheme after previously showing they seemed to have no clue.

  Smartly, they rebuilt the foundation, committing significant resources to improving the defensive front. The most important area was the Redskins’ weakest, prompting internal discussions on the need to do things right for a change.

 Assistants implored Coach Mike Shanahan to focus on the line during the draft and free agency, several Redskins people tell you, figuring it was time to get serious after mostly working with the wrong pieces up front.

 Shanahan thought the Redskins could muddle through with defensive linemen who would have been backups on ballclubs such as Pittsburgh and Green Bay, the other teams that play the aggressive 3-4 style the Redskins only dabbled in.

 His approach resulted in Washington’s defense ranking second to last in the 32-team league. It was the team’s worst performance statistically in 56 years.

 It was a disaster from start to finish, and “it was pretty clear we needed to make some changes,” Pro Bowl inside linebacker London Fletcher said recently. “I didn’t know what the plan would be, what direction we’d go, but you can definitely see where [management] was looking.”

Shanahan and General Manager Bruce Allen focused on what they should have from the start: getting the line straight. The Redskins used their first- and second-round picks on outside linebacker Ryan Kerrigan and defensive end Jarvis Jenkins. Then they spent wisely in free agency, luring defensive linemen Barry Cofield and Stephen Bowen from NFC East rivals.

Suddenly, the Redskins have potential. They have the look of a team not only determined to run a 3-4, but a good one.  Now, they can get rolling. The task of transitioning from their long-standing 4-3 is really underway because they upgraded the talent.

 Friday marked an important starting point for a franchise trying to build an entire roster the traditional way for the first time in the Daniel M. Snyder era.

It’s all uncharted territory.

In 2010, the Redskins stuck their toes in the water with the 3-4. This time, they’ve dived into the deep end.

The next phase is to find out what they’ve got.

 From watching practice at Redskins Park, the coaching staff has learned Kerrigan is strong. He has the power needed to become an effective edge rusher.

How will the converted 4-3 college end, however, handle his coverage responsibilities? Is the rookie athletic enough to adjust when his strength is, at times, nullified while battling against the NFL’s grown men?

 Jenkins has impressed coaches as well. He’ll be a key member of a six-man rotation along the line. It doesn’t matter whether he plays behind Adam Carriker. He’ll play a lot regardless off his standing on the depth chart.

But how long will it take for Jenkins to refine his rough rookie edges?

Cofield is the new starting nose tackle after playing as a 4-3 tackle for his first five seasons with the New York Giants. Although he occasionally lined up over the nose in some of the Giants’ packages and played the position in college, he’ll work primarily in that spot for Washington.

 He’s listed at 306 pounds. That’s on the light side for his job.

Cofield doesn’t reveal his actual weight, but we’ve been told he’s closer to 326 than 306, which should help him hold up. Also, backup nose Anthony Bryant showed encouraging signs during his late-season audition.

With only 11 career starts, Bowen was considered an up-and-comer while he played for Dallas. The Redskins hope he has arrived.

Washington needs its defensive linemen to be playmakers. Not necessarily guys who produce record numbers of sacks and tackles for losses — though that would be nice — but they must consistently beat blocking, especially in one-on-one matchups, and disrupt the timing of opposing offenses.

 That rarely happened last season, because the Redskins lacked the right combination of linemen. Pittsburgh and Green Bay have difference-makers there. The Redskins are trying to join their exclusive club.

 They’ll rely on Kerrigan to develop into a top performer. They expect him to complement the talented Brian Orakpo, their other outside linebacker.

They’re supposed to be bookend standouts for some time. And if the Redskins are right about Kerrigan, don’t be surprised if they give up many fewer big plays.

 Washington’s secondary is counting on pressure from both sides of the line, “because with the way we play this defense, as a corner, that’s what you need from those guys,” Pro Bowl cornerback DeAngelo Hall said recently. “You get it from both sides, that’s when you’ll see what this defense can really do.”

 Redskins fans weren’t so fortunate last season. The product didn’t match the plan. But the preseason is all about new beginnings. Or simply getting started.