JACKSONVILLE, Fla. -- The Jacksonville Jaguars opened 2021 NFL training camp Tuesday at TIAA Bank Field. Here’s a closer look at a few storylines:

The bar for rookie QBs is pretty high. Will Trevor Lawrence be the next to surpass 4,000 yards and can he threaten Justin Herbert's record of 31 TD passes?

Since receiver is the Jaguars’ best position group on offense, Lawrence should at least threaten the 4,000-yard mark, but whether he becomes the fifth rookie QB in NFL history to surpass it will depend on the defense. Last season’s unit gave up the most yards and points in franchise history and while coach Urban Meyer and GM Trent Baalke did a very good job rebuilding the secondary, there are still major questions about the defensive line and pass rush. If the Jaguars again find themselves trailing by double digits in the second half of games, they’ll have to rely on Lawrence pretty heavily. The TD mark seems more reachable, even if the Jaguars aren’t always chasing points, because of the addition of WR Marvin Jones Jr. and RB Travis Etienne to a group of playmakers that includes WR DJ Chark Jr. (Pro Bowl in 2019), RB James Robinson (1,070 yards as a rookie in 2020) and spring standout WR Laviska Shenault Jr.

What does tight end Tim Tebow have to show during camp and the preseason to make the 53-man roster?

We already know he’s a good athlete and has good hands, so it will come down to how well he can block. There are a lot of fundamentals -- such as hand placement and footwork -- that he’ll be learning for the first time and nobody’s sure how he’ll do until the pads go on in camp. Can he set the edge in the run game? Can he handle a defensive end in pass protection? Chris Manhertz, James O’Shaughnessy and rookie Luke Farrell appear to be locks to make the roster, so there may be only one spot available. Second-year player Tyler Davis did some good things in the spring and Meyer said Ben Ellefson was one of the unit’s most improved players, so Tebow has a hard road ahead. A caveat, though: This all applies if Meyer’s plan is use Tebow only as a traditional tight end. If he’s going to use Tebow as a gadget guy -- line up at H-back, take Wildcat snaps in short-yardage situations, some trick plays (double passes?) -- then Tebow’s chance of making the roster go up significantly. Meyer said he was going to wait until camp to figure out a plan for Tebow, so that should become clearer within the first couple of weeks.

With the addition of Carlos Hyde and Etienne, what are legitimate expectations for Robinson?

One of the best support systems for a young QB is a run game, so that’s why the Jaguars added Hyde, Etienne and, just as importantly, Manhertz, who is regarded as one of the league’s best blocking tight ends. Hyde and Etienne will take some carries away from Robinson, but remember that Etienne will be moved around and line up out wide and in the slot, as well. Robinson had 240 carries last season, but nobody else had more than 32 and that will change this season. You shouldn’t expect Robinson to duplicate his 49 catches, either. Still, this offense has the potential to score a lot of points and if the Jaguars can get second-half leads, Robinson should get a lot of work. Another 1,000-yard season isn’t out of the question, but with the additions in the backfield sharing the workload it makes it tougher. One stat to know: Darrell Bevell has had a 1,000-yard rusher in nine of his 14 seasons as an offensive coordinator -- Adrian Peterson (four times), Marshawn Lynch (four times) and Chester Taylor -- but hasn’t had one since 2014.

The defense is switching from a 4-3 to a 3-4 and the personnel isn’t exactly a perfect match, so how will the Jaguars manufacture pass rush?

The move to outside linebacker is good news for Josh Allen (12.5 career sacks), because he excelled there at Kentucky and was the SEC’s Defensive Player of the Year as a senior (17 sacks). It should also help K’Lavon Chaisson, who had just one sack last season as a rookie, because he played there at LSU. But other than Allen, the only other player on the roster with double-digit career sacks is DE Dawuane Smoot (11.5). DC Joe Cullen said he’s going to use a lot of blitzes -- LB Joe Schobert said roughly half the plays the defense ran in the spring were blitzes -- and try to confuse offenses with formations, so the QB is unsure which players may be rushing and which will be dropping. Cullen also said the work the Jaguars did in the secondary -- adding CB Shaquill Griffin and S Rayshawn Jenkins and drafting CB Tyson Campbell and S Andre Cisco -- will help out the rush, because they should be able to hold coverage a little longer to help the rushers get home.