Baltimore Ravens' fans began the 2018 season with the belief that their roster was built to put them into contention. Early on in the regular season, those hopes began dwindling with Joe Flacco under center.

With Flacco, the Ravens stood with a record of 4-5 through the first nine weeks of the season. Then, Baltimore turned to their rookie quarterback in Lamar Jackson following the bye week in Week 10.

Jackson immediately provided a spark to a downtrodden offense and led the Ravens to an impressive 6-1 record to end the year. The Ravens were able to implant a dominant rushing attack with Jackson spearheading the offense.

A duo of Gus Edwards and Jackson helped propel Baltimore into the playoffs but their power-running scheme became too predictable. As a result, the Ravens fell to the Los Angeles Chargers in the AFC Wild Card Round.

Despite the loss, the Ravens made good progress with Jackson at the helm. Although, the young quarterback has some kinks to work out in his game moving forward.

In 2019, the Ravens are in a good spot to defend their AFC North crown. Every team in the NFL has areas where they can improve or areas where they should be concerned about. Here are three areas of concern for the Ravens in 2019.

C.J. Mosley, Ravens

3. Replacing Terrell Suggs, Za'Darius Smith, C.J. Mosley

This offseason, the Ravens saw three of their key contributors on defense leave during free agency. Even Terrell Suggs left after spending 16 seasons with the franchise.

Nonetheless, Baltimore will need to replace the immense amount of production that all three of their losses helped produce. Most importantly, the Ravens need to replace C.J. Mosley in the middle of their defense. Plus, finding the edge rushers to replace both Suggs and Za'Darius Smith.

Currently, the Ravens likely will move Patrick Onwuasor to Mosley's spot and promote Kenny Young to the other inside linebacker spot. Onwuasor has displayed his potential on the defense with 157 tackles in the last two seasons. Young also flashed his promise last season with 51 tackles.

At the outside linebacker positions, the Ravens will have both Tyus Bowser and Matthew Judon replacing Suggs and Smith. Judon may be one of the best pass rushers that no one talks about. Replacing Suggs, Smith, and Mosley may not be easy but the Ravens have the personnel to do so.

Skip Bayless, Marquise Brown, Ravens

2. The Wide Receivers

Last season, the Ravens saw minimal production from their wide receiver group. During the regular season, the Ravens ranked 23rd in the NFL with just 3,708 yards coming from their pass catchers.

This offseason, John Brown left for the Buffalo Bills but the team drafted Marquise Brown to add some much-needed speed to their aerial attack. Besides Brown though, Baltimore's receiving corp is pretty thin outside of Willie Snead.

After the Ravens turned towards being a run-heavy offense in 2018, they will need to be able to throw the ball with more effectiveness in 2019. That means the wide receivers need to step up in a huge way in the upcoming season to help Jackson develop further as a quarterback.

In 2018, the Ravens had 28 drops by their whole team with Michael Crabtree, Brown, and Snead accounting for 20 of them. Crabtree and Brown are no longer there so the new-look receiving corp will need to perform better than last year's group.

Lamar Jackson

1. Lamar Jackson

The biggest question mark surrounding the Ravens is how will Lamar Jackson perform in his second season in the NFL? Teams now have game tape on how to slow him down on the ground after the Chargers held him in check in the playoffs.

If Jackson is going to take the next step in his career, he needs to be able to throw the ball with more positive results. Last season, Jackson completed just 58% of his passes while throwing just 1,201 yards and six touchdowns in his seven starts.

Fumbling also became an issue for the mobile quarterback as he had 12 of them during the regular season and three of them against the Chargers in the playoffs. The success of the Ravens offense relies solely on how Jackson improved himself as a thrower.

Undoubtedly, Jackson is very dangerous as a runner but will need to be able to pair that with an ability to throw the ball downfield. The Ravens don't need to prevent him from running still as that's what makes him dangerous but having him throw more will be a focus for John Harbaugh and the Ravens in 2019.