LANDOVER, Md. - A HALF HOUR after the sweet merciful sound of the final gun, Halapoulivaati Vaitai was once again alone on an island, trapped inside a small circle of space that had been afforded to him by a crowd of reporters who had gathered at his locker to hear the first-person account of the manhandling that all of them had witnessed. He was wearing a black T-shirt with his number on the back and a personalized moniker above it: THE QUIET ONE, it said.

Quiet or not, there were no words, and everybody seemed to understand it. Rookies who last until the fifth round aren't typically asked to step right out of a college spread offense and into a one-on-one matchup with a grown man of a pass rusher the way the Eagles asked Vaitai to do on Sunday against the Redskins' Ryan Kerrigan. As expected, he'd spent much of the afternoon stumbling backward, trapped in a sort of inverted undertow created by the relentless bull rush of Kerrigan, a defensive end who tallied two of his team's five sacks while working opposite Vaitai. During the massacre, Eagles coach Doug Pederson did everything he could to limit Vaitai's exposure. Afterward, he transitioned directly into the delicate process of rebuilding the kid's confidence, insisting that he had not and would not consider looking elsewhere to fill the gaping void created by Lane Johnson's 10-game suspension.

But there is no way anybody could have watched the game and come away with a conclusion other than this: The Eagles have a huge problem at right tackle, and they'll have a huge problem on the scoreboard until they find a fix.

"Lane is a big part of what we were doing and he was playing well; it is disappointing from that standpoint," Pederson said, "but at the same time, we're handed these cards and we're going to play with the best five guys up front. It is our job as coaches, it is what we are hired to do, to make our players better. We are going to do that this week."

None of what we saw in Sunday's 27-20 loss should have come as a surprise, given how well Johnson had played during the Eagles' 3-1 start, and given that Vaitai was a fifth-round pick who spent his college career playing in Texas Christian's spread offense where he wasn't often asked to hold blocks against 265-pound defensive ends exploding off the ball from three-point stances.

The biggest question about this Eagles team has always been its depth across the board, and we're beginning to see its effects. Take, for instance, the situation in the secondary. Byron Maxwell and Eric Rowe didn't appear to be any good, but they were bodies, and the Eagles have a severe shortage of that kind of thing in the defensive backfield. There's a reason Malcolm Jenkins moved from cornerback to safety early on in his NFL career. He simply does not have the foot speed to match up with the more fleet-footed of opposing pass-catchers, and we saw two costly demonstrations of that truth on Sunday. That kind of thing is going to happen when you only dress three cornerbacks.

Then there was the defensive line. After Bennie Logan went down with a groin injury, the Redskins began to gash the Eagles with their zone runs, most of which were angled directly at Connor Barwin and Beau Allen on the right side of the Eagles' defensive line (though the presence of All-Pro tackle Trent Williams on the left side of the Redskins' line had something to do with the play direction as well).

But the depth has always been most precarious - and most pivotal - on the offensive line. Johnson's suspension has created the glaring deficiency that many feared would develop on the opposite side of the line, where left tackle Jason Peters has played quite well despite a 34-year-old body that betrayed him for much of last season. In the process, it has illuminated one of the underacknowledged truths about the Eagles' success leading into Week 6. As impressive as rookie quarterback Carson Wentz has been - despite the loss, he again had his moments - the play of the offensive line was the most important factor in the Eagles' 3-0 start. In fact, it has been the most important factor in virtually everything we've seen with this Eagles' offense since Andy Reid's second year at the helm, and one can argue that Sunday's disaster showed the importance of finding not only a short-term answer to fill in for Johnson over the next nine weeks, but a long-term answer to step in for Peters after this year or next.

Remember, from 2000 through 2008, the Eagles played just 10 regular-season games in which Jon Runyan and Tra Thomas did not start together at right and left tackle, respectively. Six of those games came in the 2005 season, when Thomas missed the last seven weeks due to injury. The Eagles went 6-10 that season. In 2009, Peters replaced Thomas at left tackle, while Winston Justice replaced Runyan. Peters has started at least 13 games in every season since except 2012, which he missed after rupturing his Achilles'.

In other words, the Eagles' two worst seasons since 1999 - the only two seasons they posted a losing record between 2000-14 - have come in the two seasons when their left tackle missed an extended stretch of games, and the decline phase of the Reid regime coincided with their search for a tackle to start opposite Peters: first came Justice, then Todd Herremans, and then, in 2013, Lane Johnson.

Whenever a team has a weakness at one of the island positions, there is a trickle-down effect, and you saw it throughout Sunday's loss. The Eagles spent most of the game running their offense away from Vaitai's side. Their running backs carried the ball left. Their quarterback shifted his pocket left. Darren Sproles and Zach Ertz routinely incorporated chip blocks into their routes to assist Vaitai.

On the few occasions Wentz had time to throw, you saw the promise of this offense with him at the helm: A seam pass to Ertz that traveled 22 yards before the defenders could react to its release. An effortless 23-yard throw to Dorial Green-Beckham in the middle of the field. A beautiful 54-yard deep ball that hit Jordan Matthews in stride and set up a field goal.

But even the most talented of quarterback's is near worthless if his offensive line can't block four with five. One need only look to Indianapolis to see an example of this truth. The Eagles' offensive tackle issue isn't going away even after Johnson comes back. Vaitai or elsewhere, the success of the whole thing could hinge on finding a solution.

@ByDavidMurphy

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