The Philadelphia Eagles are looking forward to building their roster after the NFL free agency period.

After winning Super Bowl LII, the Eagles struggled as the 2018 NFL season wound down. They went 5-6 in their last 11 games after a promising 4-1 start. They were fortunate to benefit from a missed Cody Parkey field goal attempt in the NFC Wild Card game to advance to the divisional round. Unfortunately, the New Orleans Saints beat them, 20-14.

Are the Eagles regressing?

It's too early to tell. However, quarterback Carson Wentz should come back with a clean bill of health in September. Philadelphia also has added running back Jordan Howard and re-acquired wide receiver DeSean Jackson. These moves alone should excite Eagles fans to no end.

Philadelphia has a few holes to plug after the free agency period. Let's break down the Eagle's three biggest needs.

3. Linebacker

The Eagles' defense took a major step backward last season. They were fourth in the league in total defense the year they won the Super Bowl (4,904 yards allowed). A year later, they fell to 23rd in the NFL, allowing a total of 5,859 yards.

One position which needs shoring up is linebacker. If the Eagles can fortify their pass rush, they will go places. Philadelphia was the third-worst team against the pass in 2018, allowing 4,308 yards in the air.

Adding a big-name outside linebacker such as Jadeveon Clowney is a tall order (the Eagles have approximately $21 million in cap space as of April 3). However, if Eagles executive vice president of football operations Howie Roseman can make it happen, it should turn Philly's fortunes around.

The Texans placed the franchise tag of $17.128 million on Clowney on March 5. Getting Clowney, who earned a base salary of $12.306 million in 2018, would likely cost the Eagles two first-round draft picks.

Ronald Darby

2. Secondary

Simply put, Philadelphia's secondary was terrible in 2018 – it was the main reason why the Eagles allowed so many passing yards last season. Two major factors came into play: injuries and inconsistency.

While adding veteran safety Andrew Sendejo and re-signing cornerback Ronald Darby were good moves, the Eagles should maintain some semblance of consistency at secondary. It all starts with being healthy. Granted, teams cannot avoid injuries in a bruising sport such as football.

However, Philadelphia cannot afford another slew of injuries to hit their secondary in 2019. Head coach Doug Pederson can only hope this crew exceeds expectations. If not, look for Philly to make a key trade or two in the upcoming NFL season.

Frank Clark

1. Defensive End

One interesting target for Philly is Seattle Seahawks defensive end Frank Clark. The main reason: Clark had a career-high 13 sacks in 2018. He also has 35 sacks in 33 starts. If that doesn't get the Eagles' attention, nothing will. He's the type of edge rusher this team needs.

Clark fits the mold Eagles defensive coordinator Jim Schwartz wants – an aggressive, attacking defensive lineman who disrupts the offense, pressures the quarterback constantly, and doesn't just play at the line of scrimmage. It's not hard envisioning Clark as a key piece in Schwartz's 4-3 defense.

The Seahawks placed the franchise tag on Clark (worth $17.1 million for defensive ends) on Clark on March 4. Should Philadelphia land Clark, they will need to send a good return to Seattle.