Leonard Fournette was the fourth pick in the 2017 NFL Draft and as a rookie he had an immediate impact on the Jaguars' offense. He started 13 regular season games and rushed for 1,049 yards (3.9 YPC) and nine touchdowns. In three playoff games, he ran for 242 yards and four scores -- including 109 yards and two touchdowns against the helpless-to-do-anything-about-him Steelers in the AFC Divisional round.

But Fournette, who at six feet, 228 pounds is hard to miss and even harder to stop, at times became too big a target for would-be tacklers.

″I think as a young player getting to this level and then he really ran hard and did a really good job," offensive coordinator Nathaniel Hackett explained, via the Florida Times-Union's John Reid. "But I think he almost took too many hits. I just want him to be able to understand the system more so he can run even smarter, but still never lose that aggressiveness.″

Fournette's presence coincided with quarterback Blake Bortles' most consistent season; the much-criticized 2014 first-round pick completed 60 percent of his passes in 2017, including 21 touchdowns against 13 interceptions. He ranked 15th among all quarterbacks in total value, according to Football Outsiders, an improvement from 23rd the year before, 25th in 2015 and 44th his rookie season. The Jaguars offense improved from 27th in '16 to 16th in '17 and finished with a winning record for the first time since 2007.

Put another way: Fournette is important but the Jags will only go as far as Bortles can take them.

"When we started [offseason workouts] last year, it was kind of an elementary level, in terms of 'I'm hearing the play, I'm thinking about the footwork I have to take, the identification, trying to remember what routes guys are running and all that,'' Bortles said, via Reid. "Now, I think I'm kind of owning the offense and having a better understanding of it. Obviously, it is a continuous study and a continuous grind to continue to master it and stay on top of it, but I definitely feel more comfortable with it."

The Jaguars certainly hope so; in February they gave him a three-year extension worth $54 million. And while there was speculation heading into the offseason that an upgrade at quarterback to push the Jaguars over the top in the AFC given the quality of their defense, that would have necessitated cutting ties with Bortles, paying a free-agent top dollar, and potentially forgoing filling other holes on the roster.

Instead, the Jags elected to stay the course with Bortles. They acquired Browns backup Cody Kessler this offseason, and drafted Nebraska's Tanner Lee in the sixth round, but neither is a threat to unseat Bortles, who enters his fifth season.

"The one thing we have been talking to players about is being accountable for each other,'' coach Doug Marrone said. "What is going to make us a team is when we are accountable to each other the same way that I expect the players to hold me accountable as the head coach. I think the more you know someone, the more you know what they have been committed to and some of the issues they have."