Jacksonville owner Wayne Weaver chose Del Rio despite his limited coaching experience to lead his franchise past the dour, dictatorial past of fired coach Tom Coughlin. Meanwhile, it's still possible that Ravens director of college scouting Phil Savage, who remains a candidate for the Seattle Seahawks general manager opening, may not become the Jaguars' personnel boss as contract negotiations reportedly hit a snag late Friday night.
Expect Harris, Tom Modrak or Rick Reiprish to get the job if Savage balks and pursues the Seahawks' job.
Del Rio's ascension is being trumpeted by his former employers, the Ravens, whom he helped win a Super Bowl title just two seasons ago through his work with All-Pro middle linebacker Ray Lewis and Co.
"He was an outstanding linebackers coach for us," Ravens owner Art Modell said. "He was very instrumental in the development of Ray, Peter Boulware, Jamie Sharper and Cornell Brown. He has the potential to become a top-level NFL head coach, and I believe he will achieve that."
Del Rio, 39, becomes the second-youngest coach in the league behind Jon Gruden.
In a 10-7 victory over the Ravens during the regular-season opener in Charlotte, N.C., last September, Del Rio couldn't hold back his exuberance after the game-sealing interception by linebacker Dan Morgan. He sprinted onto the field and pounded his way into a sea of celebrating bodies.
Del Rio was an All-American linebacker at Southern Cal, where he was a finalist for the Lombardi Award. His experience and rugged physique lends him instant credibility with NFL players.
"Jack played the game," Lewis said. "He enjoyed it when he played and he takes that same approach with coaching. He makes hard work fun. He will be a great head coach, and I really think that he will be successful because his players can relate to him.
"Jack is a very hands-on coach and one of the coolest coaches that I have ever played for. We always enjoyed being around each other, but when it was time to work, we worked."
Added Boulware: "He only stopped playing the game a few years ago, and I believe that he still has a fresh perspective of today's game. I think this was a great move for the Jaguars' organization."
Del Rio was a third-round choice by the New Saints in 1985. During his playing career, Del Rio recorded 1,078 tackles, registered 12 quarterback sacks and collected13 interceptions.
He retired in 1995, spending one year with the Saints' staff as an assistant strength and conditioning coach before latching on to Brian Billick's staff in Baltimore for the next three seasons.
"Jack's is an excellent young coach and has a huge future in this profession," said Billick, whom Del Rio credited at his Friday night introductory press conference in North Florida for helping him with his motivational and organizational skills. "He is very capable of being a head coach in this league and that is a great opportunity for him that we, here at the Ravens will support whole-heartedly."
The Jaguars experienced a combined record of 19-29 over the last three seasons, including consecutive 6-10 campaigns that spelled the end of the Coughlin era.
Tough decisions loom on the future of veteran quarterback Mark Brunell, who carries a significant salary-cap figure, along with the health of defensive end Tony Brackens and the impending contract negotiation of talented running back Fred Taylor.
Early speculation has centered around Ravens linebackers coach Mike Smith and Ravens defensive line coach Rex Ryan possibly joining Del Rio as defensive coordinator candidates. Baltimore tight ends coach Wade Harman has been mentioned as a possibility for the offensive coordinator role.
"I enjoyed working with Jack," Ravens general manager Ozzie Newsome said. "He brings a certain degree of energy when you are in his presence. He is a very knowledgeable evaluator and has a big-picture outlook.
"Jack is a guy that showed me he can be a general and a soldier, meaning he can be a leader, but he is not afraid to get down and dirty by doing the fundamental things that it takes to be successful."
NOTE: With former Ravens and Washington Redskins defensive coordinator Marvin Lewis being blocked by owner Arthur Blank when he tried to hire Atlanta Falcons secondary coach Emmit Thomas to join his staff in Cincinnati, it's possible that Ravens secondary coach Donnie Henderson, could emerge as a candidate for that job again.