Watch Now: How Ravens Fulfill Super Bowl Aspirations (3:44)

There isn't much Lamar Jackson can do to improve upon a tremendous 2019 season, one in which he was the unanimous MVP of the league. Jackson led the Baltimore Ravens to the highest-scoring offense in football, setting a league record for rushing yards by a quarterback in a season. 

Even with all the success, the Ravens bowed out of the NFL playoffs in the divisional round -- despite having home-field advantage in the AFC. Harbaugh saw the flaw in Jackson's game during that playoff loss to the Tennessee Titans, and it's an area he wants the MVP to improve this offseason

"Those corners are going to be one-on-one and those safeties are going to be one-on-one against receivers, especially on downfield throws, and we got to make them pay for it," Harbaugh said during a conference call last week, per the Ravens website. "I really do believe that's the next step for this offense from an execution standpoint. 

"I really do believe Lamar is going to take the next step and our receivers are going to take the next step."

Jackson became the first quarterback to throw for over 3,000 yards and rush for over 1,000 yards in a single season. He also had the most rushing yards by a QB in a season in NFL history (1,206), leading the league with 6.9 yards per carry and finishing with seven touchdowns. Jackson completed 66.1 percent of his passes for 3,127 yards, 36 touchdowns and six interceptions for a 113.3 passer rating. He led the NFL in touchdown passes and touchdown percentage (9.0) and his 43 total touchdowns led the league. 

Jackson was the AFC Offensive Player of the Week five times and was the AFC's Offensive Player of the Month for November. In the final eight games he played in the regular season, Jackson completed 69.4 percent of his passes for 1,477 yards, 25 touchdowns and just one interception. He also had 630 rushing yards and four rushing touchdowns. 

It'll be hard to top what Jackson did in 2019, so for Harbaugh to say Jackson needs to improve on deep passes may be a bit of a stretch. Jackson completed 39.7% of his deep passes for 829 yards, 12 touchdowns and two interceptions last season, ranking amongst the best in the NFL

Perhaps Harbaugh wants the completion percentage to be better, but Jackson's best may be yet to come.