Quite a few starting spots are up in the air, and rotation along the D-Line is a huge question mark. 
Secondary packages and personnel need sorting out and three players there are out with the virus. 

Tell us what you see going on with the various battles to earn playing time.

Here's something from PFF to spark a convo:

https://www.pff.com/news/nfl-three-train...s-2021#JAX

Quote:INTERIOR DEFENSIVE LINE: TAVEN BRYAN VS. JAY TUFELE VS. ADAM GOTSIS
Jacksonville is expected to move to a base 3-4 defense in 2021 under new defensive coordinator Joe Cullen. Offseason acquisitions Roy Robertson-Harris and Malcom Brown are the two most likely defensive linemen to earn starting jobs in the new defense, but the third starting spot is up in the air.
Bryan may be the most interesting name in the group. Per Gary Smits of the Florida Times-Union, Jaguars defensive line coach Tosh Lupoi said of Bryan earlier this offseason, “Taven is a dangerous combination of speed and power. He has an elite skill set … we just have to channel that and focus that where we need to help us the most.”
The 2018 first-round pick has yet to put it together. Tupoi and the Jaguars will be hoping 2021 is the year he finally does.

NO. 3 CORNERBACK: TYSON CAMPBELL VS. TRE HERNDON VS. SIDNEY JONES
Campbell played just 65 snaps in the slot during his college career, but he’s expected to compete for the starting nickel job in Jacksonville as a rookie.
New head coach Urban Meyer said of Campbell on The Cris Collinsworth Podcast, “He played safety in high school and he was a state champion in Florida in the 100 (meters), and we’re going to dual-teach him right out of the gate corner and nickel.”
Herndon will be Campbell’s primary competition for the starting nickel job. He earned a 55.8 coverage grade across 531 wide snaps in 2020 compared to a 58.9 mark on 306 slot snaps.

FREE SAFETY: ANDRE CISCO VS. JARROD WILSON VS. DANIEL THOMAS
Cisco is still working his way back from an ACL injury that prematurely ended his 2020 season at Syracuse, but his range and playmaking ability could make him a surprise starter at free safety if he’s cleared. Cisco tallied 26 combined interceptions and pass breakups in 24 career college games.
Wilson is the favorite to start as things stand, though. He has been one of the steadier presences on the Jaguars' defense over the past two seasons, earning a 72.3 overall grade across nearly 2,000 defensive snaps since 2019.

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