Signed as a marquee free agent in 2003, former Florida Gators standout Mike Peterson arrived in Jacksonville after four productive seasons with the rival Indianapolis Colts. Stepping straight into the middle linebacker spot, Peterson brought fiery leadership and sideline-to-sideline range to North Florida, immediately serving as the operational quarterback for defensive coordinator Mike Smith's unit.

Peterson wasted no time making an impact, surpassing 100 combined tackles in each of his first three seasons in teal and black. His peak performance came in a stellar 2005 campaign, when he recorded 132 combined tackles, 6.0 sacks, 10 tackles for loss, and three interceptions—including a 26-yard pick-six against the Bengals—earning him Second-Team AP All-Pro honors. Despite turning in a performance widely regarded as Pro Bowl-caliber, Peterson was inexplicably snubbed from the all-star roster. 

Injuries and a midseason coaching dispute curtailed his final three years in Jacksonville, but he remained a crucial defensive anchor through 2008 before finishing his 14-year NFL career with the Atlanta Falcons. With the Jaguars, he had 15.0 sacks, 546 combined tackles (400 solo, 146 assists), 32 tackles for loss, 20 pass deflections, and eight interceptions.

Selected 28th overall in the first round out of UCLA in the 2006 NFL Draft, John Mackey Award winner Marcedes Lewis arrived in North Florida charged with upgrading Jacksonville's passing game. While critics often pointed to his moderate box-score receiving totals over a 12-season stay, Lewis proved to be far more than just a pass-catcher, using his massive frame and exceptional inline blocking ability to function effectively as a sixth offensive lineman.

Lewis achieved the pinnacle of his receiving performance during a significant 2010 season, recording career highs across various metrics with 58 receptions for 700 yards and a franchise-record 10 receiving touchdowns. This outstanding season earned him his first Pro Bowl selection and Second-Team AP All-Pro honors. Beyond his exceptional single-season performance, Lewis represented the benchmark for tight end longevity and resilience in Jacksonville, serving as an essential component in sealing edge blocks in the running game for twelve years and bridging several offensive eras through his consistent leadership.

After departing Jacksonville in 2018, Lewis extended his remarkably durable NFL journey into his late 30s and 40s with Green Bay, Chicago, and Denver, eventually becoming the all-time NFL record holder for games played by a tight end. However, he forged his legacy over more than a decade of hard-nosed work in North Florida.

Lewis had 4,502 receiving yards and 33 receiving touchdowns for the Jaguars.

Before the 2003 NFL Draft, Vince Manuwai made headlines at the combine by bench-pressing 225 pounds 35 times, signaling the sheer functional strength he brought from Hawaii to North Florida. Placed into the starting lineup at left guard as a third-round pick (72nd overall), he adapted instantly to the speed of the professional game, starting 12 contests as a rookie and claiming a spot on the PFWA All-Rookie Team.

Manuwai quickly emerged as the bone-crushing engine behind Jacksonville's premier rushing attack. Playing alongside center Brad Meester, his aggressive, physical blocking at the point of attack regularly cleared wide lanes for Fred Taylor and Maurice Jones-Drew during the team's most potent mid-2000s offensive campaigns. Manuwai produced his finest football during the 2006 and 2007 seasons, serving as the lead interior blocker for back-to-back top-three NFL rushing offenses—including a franchise-record 2,541 rushing yards in 2006. Though a torn ACL interrupted his momentum in 2008, he battled back to reclaim his starting job and anchor the line for two more seasons before concluding his eight-year playing career spent entirely in Jacksonville.

He would make 105 starts in 111 games over his career.

After entering the league as a second-round pick with Buffalo, middle linebacker Paul Posluszny signed with Jacksonville in 2011 and proceeded to outshine his solid early career, becoming the central nerve center for the Jaguars' defense over the next seven seasons. Combining classical linebacking instincts with remarkable durability, Posluszny served as a relentless tackling machine, commanding the defense through various defensive shifts and rebuilding years.

Posluszny’s peak performance arrived during the 2013 season, when he earned his lone career Pro Bowl selection after leading the entire NFL with 122 solo tackles while adding 162 combined tackles, 3.0 sacks, and two interceptions (including a 59-yard pick-six). Over his tenure in North Florida, he produced five seasons with at least 119 combined tackles and cracked triple digits in solo tackles three times. In his final season in 2017, Posluszny adapted seamlessly to a reduced rotational role, providing veteran leadership that helped power Jacksonville's defense to the AFC Championship Game before he officially retired in the spring of 2018.

With Jacksonville, he compiled 13.0 sacks, 816 combined tackles (587 solo, 229 assists), 45 tackles for loss, 36 pass deflections, 11 interceptions, four forced fumbles, and two fumble recoveries.