The Philadelphia Eagles brought back an old friend this offseason, signing wide receiver DeSean Jackson.

Jackson spent the first six seasons of his career with the Eagles from 2008 through 2013, making three Pro Bowl appearances and finishing with over 1,000 yards three times.

Since then, Jackson has produced mostly disappointing results, spending five seasons between the Washington Redskins and Tampa Bay Buccaneers and dealing with both injuries and inconsistencies throughout his time with both clubs.

But now, Jackson is back home, and while he is older at 32 years old, he is also wiser and has more experience under his belt, so he might be able to bring something significant to the table in Philadelphia.

With the Eagles going into 2019 with relatively high expectations thanks to a potentially explosive offense, Jackson could very well be the team's biggest X-factor.

Let's start with the fact that Jackson legitimately has a chance to become Philly's No. 1 wideout this coming season.

While the Eagles have a lot of depth at receiver, they don't have a whole lot of top-end talent. Alshon Jeffery has been the primary target over the last couple of seasons, but he is not really a true No. 1, so the door is wide open for Jackson to assume that spot.

Obviously, Jeffery currently holds that spot out of seniority, as the Eagles won a Super Bowl with him as the No. 1 receiver two seasons ago, but he by no means has a stranglehold on that position.

Even if Jackson doesn't overtake Jeffery as the No. 1, imagine how much of an overall impact he can have on Philadelphia's offense.

We know that the Eagles' offense particularly hinges on the health of Carson Wentz, but Jackson will add another weapon and provide Wentz a deep threat he doesn't really have otherwise.

Jeffery is mainly a possession receiver, and tight end Zach Ertz is Wentz's security blanket. Philadelphia doesn't really own a consistent downfield threat, so Jackson could potentially add another dimension to the Birds' offense.

With Jeffery, Jackson, Nelson Agholor and rookie J.J. Arcega-Whiteside, the Eagles could have one of the deepest receiver corps in the NFL in 2019. Jackson's ability to stretch the field will open up the field for Jeffery and Agholor (not to mention Ertz).

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Of course, we don't really know for sure what to expect from Jackson, which is why he is an X-factor.

The Long Beach, Calif., native has not played a full 16-game campaign since his last year in his first go-around in Philly in 2013. This past year, he was limited to just 12 games due to a thumb injury.

What's more, DeSean Jackson has not caught 60 passes since leaving the Eagles. In three of his last five seasons, he has finished with under 800 yards, so it's questionable as to how much he really has left in the tank.

For a wideout who relies so heavily on his speed, a dip in athleticism could make him nothing more than a pedestrian receiver, and it's entirely possible that has been happening over the last few seasons.

But in a better offense that is more suited to taking advantage of his talents than the Buccaneers, DeSean Jackson could end up flourishing in 2019, and the Eagles could ascend along with him.