They’re trying to build a perennial contender, but Coach Mike Shanahan and the Washington Redskins find themselves a few cinder blocks, planks and nails short. Again.

The Redskins will enter this week’s NFL draft with the 10th overall pick — consolation for going 6-10 in Shanahan’s first campaign with the franchise. And they have a high second-round pick (41st overall).

But while other teams will continue their construction projects in the third and fourth rounds, Washington will sit idle, having traded away both those picks last year. Then comes a flurry of late-round picks (two fifths, a sixth and three seventh-rounders), but chances of finding a franchise cornerstone in those rounds are slim.

The shortage of picks wouldn’t hurt quite as much in other years. But this year, the NFL’s unresolved labor dispute has so far prevented teams from signing free agents.

“When you give away picks like they have, and you’ve had a minimal amount of picks like they did last year, you’re not getting much out of the draft,” says ESPN analyst Mel Kiper. “Some teams are getting seven, eight, nine guys out of the draft, they’re getting two. The numbers will catch up to you.”

Some franchises could make do with fewer picks in a given year. But the Redskins are again paying the price for acquiring big-name players who didn’t deliver rather than building gradually through the draft. Each bust creates an additional need.

Because last year’s swap of a 2010 second-round pick and this year’s fourth-round pick for Donovan McNabb didn’t work out, the Redskins are in the market for a quarterback. Since Albert Haynesworth, the prized free agent signing of 2009, refused to play nose tackle and appears on his way out, along with McNabb, Washington also needs an anchor for the defensive line in its 3-4 scheme.

Shanahan insisted on switching from the 4-3 to the 3-4. But Andre Carter couldn’t make the transition at outside linebacker, so the Redskins need an edge pass rusher to complement Brian Orakpo.

Because Vinny Cerrato, then the team’s executive vice president of football operations, whiffed so badly in the 2008 draft, when he selected wide receivers Devin Thomas (who was cut last year), Malcolm Kelly (who was hurt all last year and has not lived up to his potential) and tight end Fred Davis (who backs up Chris Cooley) — all in the second round — Washington also needs wide receiver help.

Cornerback Carlos Rogers and right tackle Jammal Brown (who was rented from the New Orleans Saints for this year’s third-round pick) both are free agents. The Redskins haven’t been able to re-sign either one. An argument can be made for using the 10th pick on one of those positions as well.

The good news — sort of — for Washington is the team’s needs are so plentiful that a player for one of those positions probably will be available when the Redskins are on the clock.

The bad news is, even at No. 10, the team is probably just out of range of addressing its most pressing problem.

Auburn’s Cam Newton and Missouri’s Blaine Gabbert are considered the elite quarterbacks in this year’s draft. Both are expected to be gone well before the Redskins get to use their first-round selection.

The other top quarterbacks — Washington’s Jake Locker, TCU’s Andy Dalton and Arkansas’s Ryan Mallett — are considered late first-round or early second-round choices. But, there’s no certainty any of them will be available when Washington uses pick No. 41.

Texas A&M’s Von Miller is the best pass rusher in the 2011 class, but he, too, is expected to be off the board. North Carolina’s Robert Quinn could be there for Washington, but there are differing opinions about whether he is best suited to be a 3-4 outside linebacker or a 4-3 defensive end.

Alabama’s Marcell Dareus and Auburn’s Nick Fairley are the top defensive tackle prospects in the draft, but Dareus likely will be gone and Fairley isn’t seen as a good fit for the 3-4.

Both top wide receivers, Georgia’s A.J. Green and Alabama’s Julio Jones, could be drafted before No. 10 as well, and the same goes for Southern California right tackle Tyron Smith.

Given all those needs, it might serve the Redskins well to trade down, but this year, more than ever, that could be easier said than done. Because of the labor standoff, trades can involve only picks, not players.

“It’s hard to move down because we don’t know what the collective bargaining agreement is,” says former NFL executive Michael Lombardi. “If it stays status quo and we operate under 2010 rules, then not a lot of teams will want to trade into the top nine, top 10 picks because it’s just not worth it financially.

“I know the Redskins would love to move down. They would desperately like to do that. . . . But it’s really a difficult problem. When you get into the teens, it’s a bit easier because the money’s a lot more even.”

The Redskins haven’t tipped their hand about the draft, though quarterback and linebacker are believed to be their top priorities. Several times this offseason, however, Shanahan and General Manager Bruce Allen have alluded to a desire to add picks.

“Even though it looks like you don’t have any picks in the third and fourth round, there’s a possibility you can move back and get a couple of picks very quickly when you pick early in the draft like we do at 10 and 41,” Shanahan said last week.

When asked about the difficulty of having neither free agency nor third- and fourth-round picks, Allen said last week: “It doesn’t hurt right now at all. We have eight draft choices right now for this draft, and if we do well in the later rounds, then we’re not going to miss anything. Could there be some trades to acquire new picks? Yes, possibly.”

If Washington had a full complement of picks, it could draft a defensive end such as Wisconsin’s J.J. Watt or Cal’s Cameron Jordan with the 10th pick and a quarterback with the 41st pick, then look at other needs in the third and fourth rounds.

“Who could they have taken?” Kiper wonders. “An outside linebacker, maybe Chris Carter from Fresno State, maybe an offensive lineman like Marcus Gilbert from Florida, or John Moffitt from Wisconsin. . . wide receiver, Jonathan Baldwin from Pitt, Edmond Gates from Abilene Christian, Greg Little from North Carolina. Those are some of the players you’ll be missing out on in that particular area.”

But for now, the third and fourth rounds aren’t options, and so the pressure is on for Washington to hit home runs at 10 and 41.

“They have a lot of needs, so the crucial thing for them is to come out of this draft with two starters with their first- and second-round picks,” former Redskins GM and current NFL analyst Charley Casserly says. “If they can get extra picks, that would be a tremendous bonus because they need them.”