AS IT TURNS OUT, having Xavier Su'a-Filo probably would not have guaranteed that the Eagles would win the Super Bowl this season.

But later picks Trai Turner or Brandon Linder might have helped.

Su'a-Filo was the first offensive lineman drafted after the Eagles spent the 26th overall pick in the 2014 draft on outside linebacker Marcus Smith. Both Su'a Filo and Smith have had trouble getting on the field.

The Eagles declined to sign any significant free-agent offensive linemen this past offseason; overpriced, they said. The Eagles declined to draft any offensive linemen at all in the two previous drafts; no value, they said.

Instead, to the bewilderment of many NFL observers, the Eagles chose to gamble. In the offseason, they cut starting guards Evan Mathis and Todd Herremans. They let top receiver Jeremy Maclin leave via free agency, which pushed them to draft receiver Nelson Agholor in the first round.

With a fragile franchise quarterback and a sputtering running game, that gamble could cost them dearly, now that starter Andrew Gardner is done for the season with a foot injury.

The Eagles hoped for late-career development of journeymen guards Gardner and Allen Barbre, who had earned seven NFL starts between them; earned, as in, started for reasons other than injury or suspension.

For depth, they opted to lean on undrafted, athletic Matt Tobin and big, hairy veteran Dennis Kelly - again, players who never won a starting job.

Now, perhaps mercifully, the Eagles have lost Gardner to a Lisfranc injury in his right foot.

Tobin will get the first chance to start in his place.

Kelly is the only viable backup on the roster.

This is the result of, at best, questionable planning; at worst, disregard for the position.

This is remarkable, given the Eagles' recent commitment to offensive line depth. In 2011, they snagged Pro Bowl center Jason Kelce in the sixth round and guard/center Julian Vandervelde in the fifth, after a catastrophic first-round blunder with Danny Watkins. Kelly came in the fifth round of 2012. Kelly used the first pick of his NFL tenure for Lane Johnson, third overall, in 2013.

The Eagles then signed Barbre in 2013, when they added Tobin as a rookie free agent. Gardner landed as a free agent a year later.

In the past three seasons, the Eagles used picks from Rounds 2-5 on: four defensive backs, two receivers, two defensive linemen, a linebacker, a quarterback and a tight end; zero picks were used on offensive linemen. Usually, picks in those rounds represent players expected to provide depth, either immediately or in the very near future.

For example: Spencer Long, drafted 78th overall in 2014, will start at left guard for Washington in place of injured Shawn Lauvao.

The Eagles have no such reserve . . . because, again, zero offensive linemen drafted.

How could that have been different?

Rookie linemen drafted outside the first round rarely are ready to play, so give the Eagles a pass on the 2015 draft. Most likely, had they used their fourth-round pick on a lineman instead of trading it for a third-rounder in 2016, that player would have struggled.

In 2013, they took Johnson, so they wisely spend a draft asset there.

However, in 2014, a glut of intriguing linemen were available in the third round; 11 of them taken among the 35 picks. Washington had already taken Long, but five linemen were taken after the Eagles used the 86th overall to select Oregon receiver/returner Josh Huff - one of Kelly's pet Ducks who has been a disappointment in his brief NFL tenure.

Among those five taken after Huff: Turner and Linder.

Both start at guard.

Linder has been brilliant for the Jaguars, starting 18 of 19 games.

Turner is playing well for the unbeaten Panthers.

To be fair, there is no guarantee that either would have supplanted Barbre or Gardner. Barbre thrilled Eagles coaches in training camp last season, but a Week 1 ankle injury cost him the year; he has been no less (and no more) than solid through the first three games. Gardner, meanwhile, steadily improved before his injury.

Still, even if Linder or Turner were only reserves, they certainly would be less worrisome than the current fallback. After all, last season Tobin couldn't even win a job on an offensive line consistently in tatters because of injury and suspension.

Still, the Birds have no one on their roster who represents an upgrade.

"The price tag of what was available in free agency was more than what we were willing to pay," Kelly explained.

As for the draft, Kelly and Co. just didn't like what they saw when it was their turn.

"When you pick, there are probably a couple guys that go a couple picks before you that you're, 'Jeez, I wish that guy was there. If he was there, he's probably rated higher than the guy we had,' " Kelly said. "As the names get picked, you take them off and then you look at them and just say, 'Who is the best available?'

"When you reach at a position, you end up getting in trouble."

Kelly didn't actually say the words, "Marcus Smith," but he didn't have to.

Plenty of linemen taken after Huff have not panned out. Neither Turner nor Linder was a sure thing; but then, the job of a competent scouting staff is to avoid the duds and find the studs.

The knock on Turner was a lack of athleticism, and Kelly dotes on athletes.

As for Linder, he might have been too stiff and too raw for the Eagles' liking.

They aren't the only possible remedies to the current roster anxiety; but, for the moment, for a team that has drafted one offensive lineman in three years, they are the most obvious.

On Twitter: @inkstainedretch