Inside Slant: Eagles' QB mess, Cowboys' RB vacuum and more Day 3 draft takeaways

Benny Sieu/USA TODAY Sports

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NFL general managers like to say there is no finish line in building a roster, and I guess a talented player could conceivably drop out of the sky on any day of the calendar. For the most part, however, the final day of the draft marks the unofficial end of the roster-building season -- and the opening of the roster-critiquing portion of our program.

You'll see plenty of coverage in the coming days of how every team elevated itself this weekend into a Super Bowl contender. So I'll take the Donnie Downer role and point out five spots where -- by honest mistake, of course -- teams left themselves vulnerable.

Let's goooooooo ...

1. What genius would assemble a quarterback group as uninspiring as the Philadelphia Eagles'?

After failing to move up Thursday night to draft Oregon's Marcus Mariota, the Eagles appear set to take Sam Bradford, Mark Sanchez, Matt Barkley and Tim Tebow with them to training camp. Bradford is dragging a twice-torn ACL, while Sanchez (58.2 QBR) reinforced last year that he is an above-average backup and nothing more. Since 2010, Bradford and Sanchez own two of the four worst QBRs in the NFL. Coach Chip Kelly has demonstrated no faith in Barkley, and Tebow, well, yeah.

For all of the adulation Kelly has received as a forward-thinking offensive mind, much of it deserved, it's difficult to find an upside here. The Eagles are one of a handful of teams -- a list that includes the Buffalo Bills, Cleveland Browns and Houston Texans -- that don't have either an established/reliable starter or an obvious developmental prospect.

It's fair to ask what Kelly could have done during the past three days other than make a franchise-crippling trade up to get Mariota. There was a massive drop-off from Mariota to the next quarterback, Colorado State's Garrett Grayson, who was drafted at No. 75 overall.

Would the Eagles be any better off with, say, Baylor's Bryce Petty or UCLA's Brett Hundley than they are now? Perhaps. In the end, however, they finished the draft where they started it: with a major question at the game's most important position.

2. The Dallas Cowboys' offensive line is really good -- and it better be.

Since losing tailback DeMarco Murray to the Eagles, the Cowboys have signed veteran Darren McFadden -- who has never accounted for as much as half of his team's rushing yards in a season -- and that's it. Then they surprisingly passed on the position in the draft -- having watched top prospects Todd Gurley and Melvin Gordon fly off the board long before their No. 27 overall pick arrived. Their inaction means one of two things.

Either the Cowboys believe their star-studded offensive line is good enough to create extra space for whoever is in the backfield, or they're planning to acquire a veteran this summer. One conspiracy theory is reviving discussion of a trade for Adrian Peterson, even though the Minnesota Vikings have steadfastly refused to discuss it. The other theory, given the Cowboys' willingness to sign defensive end Greg Hardy and draft pass-rusher Randy Gregory, focuses on Ray Rice. For now, however, they're just theories.

Murray accounted for an NFL-high 78.4 percent of the Cowboys' rushing yards last season. The Cowboys can't possibly count on McFadden to step into that workload, but I'm not sure we have a good idea yet of who will.

3. The Indianapolis Colts' run defense could still be, uh, subpar.

As you might recall, the Colts have allowed 657 rushing yards in their past three games against the New England Patriots, the team they are chasing for AFC supremacy. And in 2014, the Colts ranked in the bottom third of the NFL by allowing an average of 2.73 rushing yards before contact -- an indicator that their front seven was handled often by offensive lines.

So what have they done to improve it? Their free-agent class includes defensive end Kendall Langford and linebacker Nate Irving, but neither has a reputation as a run-stuffer. In the draft, the Colts took only one real swing at it, selecting Stanford defensive end Henry Anderson late in the third round. Anderson did have 15 tackles for loss last season, but he is known more for his pass-rushing efficiency than his ability to hold the line of scrimmage. We shall see if the Colts have more up their sleeve.

4. The Seattle Seahawks didn't achieve much clarity at offensive line.

The Seahawks' line was so jumbled last season that their most common group of five starters played together on only 23 percent of the regular-season snaps. Then they parted ways with two starters, guard James Carpenter and center Max Unger, this offseason.

Efforts to replenish and fortify the group in the draft were limited to a pair of fourth-round picks, San Diego State tackle Terry Poole and West Virginia guard Mark Glowinski, but you wonder if they have made an organizational decision to focus elsewhere.

Offensive line coach Tom Cable is one of the best in the business. Quarterback Russell Wilson is among the NFL's most elusive quarterbacks, and running back Marshawn Lynch might be the league's best at creating his own running room. Maybe the Seahawks don't need elite personnel at all five line positions.

One concern to keep in mind, however: Wilson was pressured on an NFL-high 222 dropbacks last season. Eventually the pressure, and subsequent hits, catches up.

5. Who is going to play cornerback for the San Francisco 49ers?

The 49ers parted ways with their 2014 starters, Perrish Cox and Chris Culliver, and apparently are going to rely on the group that backed them up in 2014 to step up; they didn't select a cornerback among their 10 picks over the past three days.

In 2014, at least, the drop-off from Cox and Culliver to the rest of the 49ers' depth was steep. When they were on the field together, opponents managed 15 touchdown passes in 399 attempts. When one of them was off the field, opponents hit for another 14 touchdowns on just 151 attempts.

It's fair to point out the 49ers have three cornerbacks on their roster from the 2014 draft -- Dontae Johnson, Keith Reaser and Kenneth Acker -- along with veterans Tramaine Brock, Chris Cook and Shareece Wright. The 49ers stood pat on that group this week.

(All numbers from ESPN Stats & Information.)