After new offseason approach, Rob Gronkowski back to lead TEs

Gronk swims with Sharks (5:21)

Rob Gronkowski and Sam Alipour go diving with sharks in the Bahamas. (5:21)

In the lead-up to New England Patriots training camp, with the first public practice scheduled for Thursday, it is timely to review each position on the roster with our annual “roster locks” series. After previously highlighting the running backs, wide receivers, defensive ends, linebackers, defensive tackles, safeties, cornerbacks and offensive line, let's move on to the tight ends/fullbacks:

Locks: Rob Gronkowski, Jacob Hollister, James Develin (FB)

On the bubble: Dwayne Allen, Troy Niklas, Will Tye

Long shots: Ryan Izzo, Shane Wimann (FB)

Explaining the locks: Gronkowski earned All-Pro honors last season, and in returning for his ninth season, he said his body feels good. Last year at this time, some wondered about Gronkowski's future, as he was coming off his third career back surgery, so that's naturally been a positive development for the Patriots. In June, Gronkowski was open about his desire for a sweetened contract (similar to 2017), and that is a storyline that bears watching. The 6-foot-4, 245-pound Hollister, who made the club as an undrafted free agent from Wyoming last year, added some bulk after spending time this offseason working out in Oregon with former NFL tight end Kevin Boss. He caught the ball well in spring practices and in the 2017 preseason showed toughness in catching the ball over the middle. Some might question whether he's a roster lock, but the projection is that a second year in the system will put him in position to take another step forward. Develin, who earned his first career Pro Bowl berth in 2017, played 30 percent of the offensive snaps last season and was rewarded with a two-year contract extension.

Roster management: The Patriots kept three tight ends and one fullback on their initial 53-man roster last season and stuck with that for most of the year. Allen, a seven-year veteran, is a top-notch blocker and solid presence in the locker room. My only question with his status is how the Patriots truly view his $4.5 million base salary (plus a $500,000 roster bonus) and whether they deem it too rich for a player whose contributions come mostly as a blocker. That's why I didn't put him in the lock category. Niklas is a 2014 second-round pick who could be sparked by a fresh start after four seasons in Arizona, where injuries derailed him multiple times. Unlike Allen, he isn't an overly physical presence at the line of scrimmage as a blocker but could be a bigger factor as a pass-catcher. So he fits a different profile at the position, similar to Tye, who spent the second half of the 2017 season on the Patriots’ practice squad. Izzo was a late-seventh-round pick out of Florida State who projects as a strong practice-squad candidate. Wimann is an undrafted free agent out of Northern Illinois.

Stat of note: Gronkowski played 79.3 percent of the offensive snaps in 2017. In 2014, he played 73.4 percent, followed by 84.2 in 2015 and 31.5 in 2016.

One thing to watch for in camp: Gronkowski's strength in blocking drills. A big reason why Gronkowski has earned the respect of former NFL tight ends is that he can dominate in multiple ways -- as a blocker and pass-catcher. Once the Patriots begin practicing in full pads (July 28), it will be easier to get a feel for whether Gronkowski's offseason training approach -- he didn't take part in the team's strength program -- has had any impact on his blocking work and ability to hold up on the edge.